Methods and apparatus for overlaying electronic locate information on facilities map information and/or other image information displayed on a locate device

ABSTRACT

A locate device for a locate operation to detect a presence or an absence of one or more underground facilities is configured to access and display facilities map information, and/or other image information, as a visual aid to facilitate the locate operation. In various aspects, methods and apparatus relate to: selection of an appropriate “base” facilities map, or information from a database of facilities map data, relating to a given work site/dig area; selection of an appropriate pan and/or zoom (resolution) for displaying facilities map information; appropriately updating displayed facilities map information while a locate device is used during a locate operation (e.g. changing pan, zoom and/or orientation); overlaying on the displayed facilities map information locate information and/or landmark information relating to the locate operation; and storing locally on the locate device, and/or transmitting from the locate device, facilities map information and/or overlaid locate/landmark information (e.g., for further processing, analysis and/or subsequent display).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit, under 35 U.S.C. §119(e), of U.S.Provisional Patent Application No. 61/151,568, entitled “Locate Devicethat has a Mechanism for Viewing Facilities Maps Integrated Therein andAssociated Methods,” filed on Feb. 11, 2009.

This application claims a priority benefit, under 35 U.S.C. §119(e), ofU.S. Provisional Patent Application No. 61/151,778, entitled “MarkingDevice that has a Ticket Management Mechanism Integrated Therein andAssociated Methods,” filed on Feb. 11, 2009.

This application also claims a priority benefit, under 35 U.S.C. §120,as a continuation-in-part (CIP) of U.S. Non-provisional application Ser.No. 12/571,356, entitled, “Method And Apparatus For Analyzing Locate AndMarking Operations With Respect To Facilities Maps,” filed on Sep. 30,2009.

Ser. No. 12/571,356 in turn claims a priority benefit, under 35 U.S.C.§119(e), of U.S. Provisional Patent Application Ser. No. 61/102,169,entitled “Data Acquisition System For And Method Of Analyzing LocateOperations With Respect To Facilities Maps,” filed on Oct. 2, 2008.

This application also claims a priority benefit, under 35 U.S.C. §120,as a continuation-in-part (CIP) of U.S. Non-provisional application Ser.No. 12/649,535, entitled, “Method And Apparatus For Displaying anElectronic Rendering of a Locate and/or Marking Operation Using DisplayLayers,” filed on Dec. 30, 2009.

This application also claims a priority benefit, under 35 U.S.C. §120,as a continuation-in-part (CIP) of U.S. Non-provisional application Ser.No. 12/571,329, entitled “Methods and Apparatus for GeneratingElectronic Records of Locate Operations,” filed on Sep. 30, 2009.

Ser. No. 12/571,329 in turn claims a priority benefit, under 35 U.S.C.§119(e), of U.S. Provisional Application Ser. No. 61/102,122, entitled“Combination Locate and Marking Device with a Data Acquisition SystemInstalled Therein, and Associated Methods,” filed on Oct. 2, 2008.

Each of the above-identified applications is hereby incorporated hereinby reference.

BACKGROUND

Field service operations may be any operation in which companiesdispatch technicians and/or other staff to perform certain activities,for example, installations, services and/or repairs. Field serviceoperations may exist in various industries, examples of which include,but are not limited to, network installations, utility installations,security systems, construction, medical equipment, heating, ventilatingand air conditioning (HVAC) and the like.

An example of a field service operation in the construction industry isa so-called “locate and marking operation,” also commonly referred tomore simply as a “locate operation” (or sometimes merely as “a locate”).In a typical locate operation, a locate technician visits a work site inwhich there is a plan to disturb the ground (e.g., excavate, dig one ormore holes and/or trenches, bore, etc.) so as to determine a presence oran absence of one or more underground facilities (such as various typesof utility cables and pipes) in a dig area to be excavated or disturbedat the work site. In some instances, a locate operation may be requestedfor a “design” project, in which there may be no immediate plan toexcavate or otherwise disturb the ground, but nonetheless informationabout a presence or absence of one or more underground facilities at awork site may be valuable to inform a planning, permitting and/orengineering design phase of a future construction project.

In many states, an excavator who plans to disturb ground at a work siteis required by law to notify any potentially affected undergroundfacility owners prior to undertaking an excavation activity. Advancednotice of excavation activities may be provided by an excavator (oranother party) by contacting a “one-call center.” One-call centerstypically are operated by a consortium of underground facility ownersfor the purposes of receiving excavation notices and in turn notifyingfacility owners and/or their agents of a plan to excavate. As part of anadvanced notification, excavators typically provide to the one-callcenter various information relating to the planned activity, including alocation (e.g., address) of the work site and a description of the digarea to be excavated or otherwise disturbed at the work site.

FIG. 1 illustrates an example in which a locate operation is initiatedas a result of an excavator 1 providing an excavation notice to aone-call center 2. An excavation notice also is commonly referred to asa “locate request,” and may be provided by the excavator to the one-callcenter via an electronic mail message, information entry via a websitemaintained by the one-call center, or a telephone conversation betweenthe excavator and a technician at the one-call center. The locaterequest may include an address or some other location-relatedinformation describing the geographic location of a work site at whichthe excavation is to be performed, as well as a description of the digarea (e.g., a text description), such as its location relative tocertain landmarks and/or its approximate dimensions, within which thereis a plan to disturb the ground at the work site. One-call centerssimilarly may receive locate requests for design projects (for which, asdiscussed above, there may be no immediate plan to excavate or otherwisedisturb the ground).

Using the information provided in a locate request for plannedexcavation or design projects, the one-call center identifies certainunderground facilities that may be present at the indicated work site.For this purpose, many one-call centers typically maintain a collection“polygon maps” which indicate, within a given geographic area over whichthe one-call center has jurisdiction, generally where undergroundfacilities may be found relative to some geographic reference frame orcoordinate system.

Polygon maps typically are provided to the one-call centers byunderground facilities owners within the jurisdiction of the one callcenter (“members” of the one-call center). A one-call center firstprovides the facility owner/member with one or more maps (e.g., streetor property maps) within the jurisdiction, on which are superimposedsome type of grid or coordinate system employed by the one-call centeras a geographic frame of reference. Using the maps provided by theone-call center, the respective facilities owners/members draw one ormore polygons on each map to indicate an area within which theirfacilities generally are disposed underground (without indicating thefacilities themselves). These polygons themselves do not preciselyindicate geographic locations of respective underground facilities;rather, the area enclosed by a given polygon generally provides anover-inclusive indication of where a given facilities owner'sunderground facilities are disposed. Different facilities owners/membersmay draw polygons of different sizes around areas including theirunderground facilities, and in some instances such polygons can coverappreciably large geographic regions (e.g., an entire subdivision of aresidential area), which may further obfuscate the actual/preciselocation of respective underground facilities.

Based on the polygon maps collected from the facilities owners/members,the one-call center may in some instances create composite polygon mapsto show polygons of multiple different members on a single map. Whetherusing single member or composite polygon maps, the one-call centerexamines the address or location information provided in the locaterequest and identifies a significant buffer zone around an identifiedwork site so as to make an over-inclusive identification of facilitiesowners/members that may have underground facilities present (e.g., toerr on the side of caution). In particular, based on this generallyover-inclusive buffer zone around the identified work site (and in someinstances significantly over-inclusive buffer zone), the one-call centerconsults the polygon maps to identify which member polygons intersectwith all or a portion of the buffer zone so as to notify theseunderground facility owners/members and/or their agents of the proposedexcavation or design project. Again, it should be appreciated that thebuffer zones around an indicated work site utilized by one-call centersfor this purpose typically embrace a geographic area that includes butgoes well beyond the actual work site, and in many cases the geographicarea enclosed by a buffer zone is significantly larger than the actualdig area in which excavation or other similar activities are planned.Similarly, as noted above, the area enclosed by a given member polygongenerally does not provide a precise indication of where one or moreunderground facilities may in fact be found.

In some instances, one-call centers may also or alternatively haveaccess to various existing maps of underground facilities in theirjurisdiction, referred to as “facilities maps.” Facilities mapstypically are maintained by facilities owners/members within thejurisdiction and show, for respective different utility types, whereunderground facilities purportedly may be found relative to somegeographic reference frame or coordinate system (e.g., a grid, a streetor property map, GPS latitude and longitude coordinates, etc.).Facilities maps generally provide somewhat more detail than polygon mapsprovided by facilities owners/members; however, in some instances theinformation contained in facilities maps may not be accurate and/orcomplete. For at least this reason, whether using polygon maps orfacilities maps, as noted above the one-call center utilizes asignificant buffer zone around an identified work site so as to make anover-inclusive identification of facilities owners/members that may haveunderground facilities present.

Once facilities implicated by the locate request are identified by aone-call center (e.g., via the polygon map/buffer zone process), theone-call center generates a “locate request ticket” (also known as a“locate ticket,” or simply a “ticket”). The locate request ticketessentially constitutes an instruction to inspect a work site andtypically identifies the work site of the proposed excavation or designand a description of the dig area, typically lists on the ticket all ofthe underground facilities that may be present at the work site (e.g.,by providing a member code for the facility owner whose polygon fallswithin a given buffer zone), and may also include various otherinformation relevant to the proposed excavation or design (e.g., thename of the excavation company, a name of a property owner or partycontracting the excavation company to perform the excavation, etc.). Theone-call center sends the ticket to one or more underground facilityowners 4 and/or one or more locate service providers 3 (who may beacting as contracted agents of the facility owners) so that they canconduct a locate and marking operation to verify a presence or absenceof the underground facilities in the dig area. For example, in someinstances, a given underground facility owner 4 may operate its ownfleet of locate technicians (e.g., locate technician 6), in which casethe one-call center 2 may send the ticket to the underground facilityowner 4. In other instances, a given facility owner may contract with alocate service provider to receive locate request tickets and perform alocate and marking operation in response to received tickets on theirbehalf.

Upon receiving the locate request, a locate service provider or afacility owner (hereafter referred to as a “ticket recipient”) maydispatch a locate technician 5 to the work site of planned excavation todetermine a presence or absence of one or more underground facilities inthe dig area to be excavated or otherwise disturbed. A typical firststep for the locate technician 5 includes utilizing an undergroundfacility “locate device,” which is an instrument or set of instruments(also referred to commonly as a “locate set”) for detecting facilitiesthat are concealed in some manner, such as cables and pipes that arelocated underground; The locate device is employed by the technician toverify the presence or absence of underground facilities indicated inthe locate request ticket as potentially present in the dig area (e.g.,via the facility owner member codes listed in the ticket). This processis often referred to as a “locate operation.”

In one example of a locate operation, an underground facility locatedevice is used to detect electromagnetic fields that are generated by anapplied signal provided along a length of a target facility to beidentified. In this example, a locate device may include both a signaltransmitter to provide the applied signal (e.g., which is coupled by thelocate technician to a tracer wire disposed along a length of afacility), and a signal receiver which is generally a hand-heldapparatus carried by the locate technician as the technician walksaround the dig area to search for underground facilities. FIG. 2illustrates a conventional locate device 20 (indicated by the dashedbox) that includes a transmitter 22 and a locate receiver 24. Thetransmitter 22 is connected, via a connection point 26, to a targetobject (in this example, underground facility 28) located in the ground21. The transmitter generates the applied signal 23, which is coupled tothe underground facility via the connection point (e.g., to a tracerwire along the facility), resulting in the generation of a magneticfield 25. The magnetic field in turn is detected by the locate receiver24, which itself may include one or more detection antenna (not shown).The locate receiver 24 indicates a presence of a facility when itdetects electromagnetic fields arising from the applied signal 23.Conversely, the absence of a signal detected by the locate receivergenerally indicates the absence of the target facility.

In yet another example, a locate device employed for a locate operationmay include a single instrument, similar in some respects to aconventional metal detector. In particular, such an instrument mayinclude an oscillator to generate an alternating current that passesthrough a coil, which in turn produces a first magnetic field. If apiece of electrically conductive metal is in close proximity to the coil(e.g., if an underground facility having a metal component is below/nearthe coil of the instrument), eddy currents are induced in the metal andthe metal produces its own magnetic field, which in turn affects thefirst magnetic field. The instrument may include a second coil tomeasure changes to the first magnetic field, thereby facilitatingdetection of metallic objects.

In addition to the locate operation, the locate technician alsogenerally performs a “marking operation,” in which the technician marksthe presence (and in some cases the absence) of a given undergroundfacility in the dig area based on the various signals detected (or notdetected) during the locate operation. For this purpose, the locatetechnician conventionally utilizes a “marking device” to dispense amarking material on, for example, the ground, pavement, or other surfacealong a detected underground facility. Marking material may be anymaterial, substance, compound, and/or element, used or which may be usedseparately or in combination to mark, signify, and/or indicate. Examplesof marking materials may include, but are not limited to, paint, chalk,dye, and/or iron. Marking devices, such as paint marking wands and/orpaint marking wheels, provide a convenient method of dispensing markingmaterials onto surfaces, such as onto the surface of the ground orpavement.

FIGS. 3A and 3B illustrate a conventional marking device 50 with amechanical actuation system to dispense paint as a marker. Generallyspeaking, the marking device 50 includes a handle 38 at a proximal endof an elongated shaft 36 and resembles a sort of “walking stick,” suchthat a technician may operate the marking device while standing/walkingin an upright or substantially upright position. A marking dispenserholder 40 is coupled to a distal end of the shaft 36 so as to containand support a marking dispenser 56, e.g., an aerosol paint can having aspray nozzle 54. Typically, a marking dispenser in the form of anaerosol paint can is placed into the holder 40 upside down, such thatthe spray nozzle 54 is proximate to the distal end of the shaft (closeto the ground, pavement or other surface on which markers are to bedispensed).

In FIGS. 3A and 3B, the mechanical actuation system of the markingdevice 50 includes an actuator or mechanical trigger 42 proximate to thehandle 38 that is actuated/triggered by the technician (e.g, viapulling, depressing or squeezing with fingers/hand). The actuator 42 isconnected to a mechanical coupler 52 (e.g., a rod) disposed inside andalong a length of the elongated shaft 36. The coupler 52 is in turnconnected to an actuation mechanism 58, at the distal end of the shaft36, which mechanism extends outward from the shaft in the direction ofthe spray nozzle 54. Thus, the actuator 42, the mechanical coupler 52,and the actuation mechanism 58 constitute the mechanical actuationsystem of the marking device 50.

FIG. 3A shows the mechanical actuation system of the conventionalmarking device 50 in the non-actuated state, wherein the actuator 42 is“at rest” (not being pulled) and, as a result, the actuation mechanism58 is not in contact with the spray nozzle 54. FIG. 3B shows the markingdevice 50 in the actuated state, wherein the actuator 42 is beingactuated (pulled, depressed, squeezed) by the technician. When actuated,the actuator 42 displaces the mechanical coupler 52 and the actuationmechanism 58 such that the actuation mechanism contacts and appliespressure to the spray nozzle 54, thus causing the spray nozzle todeflect slightly and dispense paint. The mechanical actuation system isspring-loaded so that it automatically returns to the non-actuated state(FIG. 3A) when the actuator 42 is released.

In some environments, arrows, flags, darts, or other types of physicalmarks may be used to mark the presence or absence of an undergroundfacility in a dig area, in addition to or as an alternative to amaterial applied to the ground (such as paint, chalk, dye, tape) alongthe path of a detected utility. The marks resulting from any of a widevariety of materials and/or objects used to indicate a presence orabsence of underground facilities generally are referred to as “locatemarks.” Often, different color materials and/or physical objects may beused for locate marks, wherein different colors correspond to differentutility types. For example, the American Public Works Association (APWA)has established a standardized color-coding system for utilityidentification for use by public agencies, utilities, contractors andvarious groups involved in ground excavation (e.g., red=electric powerlines and cables; blue=potable water; orange=telecommunication lines;yellow=gas, oil, steam). In some cases, the technician also may provideone or more marks to indicate that no facility was found in the dig area(sometimes referred to as a “clear”).

As mentioned above, the foregoing activity of identifying and marking apresence or absence of one or more underground facilities generally isreferred to for completeness as a “locate and marking operation.”However, in light of common parlance adopted in the constructionindustry, and/or for the sake of brevity, one or both of the respectivelocate and marking functions may be referred to in some instances simplyas a “locate operation” or a “locate” (i.e., without making any specificreference to the marking function). Accordingly, it should beappreciated that any reference in the relevant arts to the task of alocate technician simply as a “locate operation” or a “locate” does notnecessarily exclude the marking portion of the overall process. At thesame time, in some contexts a locate operation is identified separatelyfrom a marking operation, wherein the former relates more specificallyto detection-related activities and the latter relates more specificallyto marking-related activities.

Inaccurate locating and/or marking of underground facilities can resultin physical damage to the facilities, property damage, and/or personalinjury during the excavation process that, in turn, can expose afacility owner or contractor to significant legal liability. Whenunderground facilities are damaged and/or when property damage orpersonal injury results from damaging an underground facility during anexcavation, the excavator may assert that the facility was notaccurately located and/or marked by a locate technician, while thelocate contractor who dispatched the technician may in turn assert thatthe facility was indeed properly located and marked. Proving whether theunderground facility was properly located and marked can be difficultafter the excavation (or after some damage, e.g., a gas explosion),because in many cases the physical locate marks (e.g., the markingmaterial or other physical marks used to mark the facility on thesurface of the dig area) will have been disturbed or destroyed duringthe excavation process (and/or damage resulting from excavation).

SUMMARY

The inventors have appreciated that, at least in some circumstances,advance knowledge of existing facilities that may be present at a worksite/dig area for a proposed excavation may be useful to a techniciandispatched to perform a locate and/or marking operation. In thisrespect, facilities maps may be a valuable resource to the technician;as noted above, facilities maps generally are maintained by variousfacilities owners and these maps typically indicate the type andgeographic location of one or more facility lines (e.g., pipes, cables,and the like) owned and/or operated by the facility owner(s). Althoughthe accuracy of facilities maps may in some cases be suspect (e.g., dueto incorrect information in the maps, age of the maps, lack of timelyrevisions that reflect the current status of deployed facilities, etc.),the various information present in many types of facilities mapsgenerally provides at least some meaningful orientation to thedeployment of underground facilities in a given area.

Accordingly, the inventors have recognized and appreciated that readyaccess to available facilities maps pertaining to a given work site/digarea may provide the technician with helpful information towardeffectively and efficiently conducting a locate and/or markingoperation. To this end, a library of facilities maps pertaining tovarious types of facilities in a given geographic area may be providedto a locate technician dispatched to the field to perform a locateand/or marking operation. For example, a library of appropriatefacilities maps may be available for viewing electronically via acomputer available at a particular work site (e.g., a laptop computer orother mobile computer disposed in the technician's vehicle).Alternatively, the locate technician may carry with them a set of paperfacilities maps in his/her vehicle. The locate technician may review thefacilities maps in their vehicle, for example, then proceed to theactual dig area to perform the locate and/or marking operation whileattempting to remember relevant information in the facilities maps.However, especially for complex facilities maps, it may be difficult forthe technician to commit to memory relevant information in thefacilities maps, and it may be inconvenient for the technician to returnto the vehicle to consult facilities maps once a locate and/or markingoperation has begun.

In view of the foregoing, various embodiments of the present inventionare directed to methods and apparatus for viewing facilities mapsinformation on a locate device used to conduct a locate operation. Inthis manner, a technician may have access to, and may view locally(e.g., immediately before, during and/or after conducting a locateand/or marking operation in a given work site/dig area), variousinformation derived from facilities maps. For purposes of the presentdisclosure, and as discussed in greater detail herein, “facilities mapsinformation” refers to any information that may be derived from afacilities map, examples of which information include, but are notlimited to, all or a portion of the imagery associated with a facilitiesmap, any underlying metadata (e.g., GIS metadata, facility typeinformation, line or symbol codes, etc.) that may accompany a facilitiesmap or set of facilities maps, and any legend information that may beincluded in a facilities map.

In various aspects, the inventive concepts discussed herein generallyrelate to one of more of the following: 1) selection, from a local orremote library/archive, of one or more appropriate “base” facilitiesmaps, or database(s) of facility map data, relating to a given worksite/dig area; 2) manual or automated selection of an appropriate panand/or zoom (resolution) for displaying, on a user interface/display ofa locate device, facilities map information derived from the basefacilities map(s); 3) appropriately updating (e.g., changing pan, zoom,orientation, etc.), if/as necessary, displayed facilities mapinformation while a locate device is used during a locate operation; 4)overlaying, on the displayed facilities map information, informationrelating to the locate operation; and 5) storing locally on the locatedevice, and/or transmitting from the locate device, facilities mapinformation and/or overlaid locate information (e.g., for furtherprocessing, analysis and/or subsequent display).

Some examples of locate devices configured to collect variousinformation relating specifically to locate operations, which locatedevices may be modified according to the inventive concepts describedherein to facilitate display of facilities map information, are providedin U.S. non-provisional application Ser. No. 12/571,329, filed Sep. 30,2009, and entitled “Methods and Apparatus for Generating ElectronicRecords of Locate Operations,” which application is hereby incorporatedherein by reference. This application describes, amongst other things,collecting information relating to the geographic location, time, and/orone or more characteristics of a magnetic field detected by one or morereceiver antennas of a locate device (e.g., “locate information”), andgenerating an electronic record based on this collected information. Itshould be appreciated, however, that the inventive concepts discussedherein in connection with display of facilities map information may beapplied generally to various instrumentation/equipment used for one orboth of a locate operation and a marking operation (e.g., a markingdevice, a locate device such as a locate transmitter and/or locatereceiver, a combined locate and marking device, etc.), as discussed infurther detail below. An example of combined locate and marking devicein which the inventive concepts discussed below may be implemented isdescribed in U.S. Non-provisional application Ser. No. 12/569,192,entitled “Methods, Apparatus, and Systems for Generating ElectronicRecords of Locate and Marking Operations, and Combined Locate andMarking Apparatus for Same,” filed on Sep. 29, 2009.

Similarly, it should be appreciated that pursuant to the inventiveconcepts described herein, facilities map information displayed on alocate device may facilitate execution of either or both of a locateoperation and a marking operation, as at least in some instances atechnician would have at their disposal, and use together, both a locatedevice and a marking device to detect and mark a presence or absence ofone or more underground facilities at a work site/dig area.

Furthermore, in addition to facilities map information, it should beappreciated that the present disclosure contemplates other types ofimage information being accessed and displayed on a userinterface/display of a locate device to facilitate various aspects of alocate and/or marking operation. For example, other types of maps (e.g.,street/road maps, polygon maps, tax maps, etc.), architectural,construction and/or engineering drawings, land surveys, and photographicrenderings/images, and various information derived therefrom, may bedisplayed on the locate device and may also be used as the basis foroverlaying locate information relating to a locate operation. As withfacilities map information, such image information and/or overlaidlocate information may be stored locally on the locate device, and/ortransmitted from the locate device (e.g., for further processing,analysis and/or subsequent display).

In sum, one embodiment of the present invention is directed to a locatereceiver to detect a presence or an absence of an underground facility.The locate receiver comprises: a housing; an RF antenna for receiving amagnetic field and outputting an output signal; a processing circuit,for receiving the output signal from the RF antenna and determining amagnetic field strength of the magnetic field; a display device coupledto the housing; at least one memory; and at least one processor, coupledto the processing circuit, the display device and the at least onememory, configured to display on the display device a map image that isgenerated based on first map data selected by the at least oneprocessor.

Another embodiment is directed to a method for displaying information ona locate receiver having a housing, an RF antenna for receiving amagnetic field and outputting an output signal, a processing circuit,for receiving the output signal from the RF antenna and determining amagnetic field strength of the magnetic field, a display device coupledto the housing, at least one memory; and at least one processor, coupledto the processing circuit, the display device and the at least onememory. The method comprises displaying on the display device a mapimage that is generated based on first map data selected by the at leastone processor.

Another embodiment is directed to at least one computer-readable storagemedium encoded with instructions that, when executed on at least oneprocessor in a locate receiver having a housing, an RF antenna forreceiving a magnetic field and outputting an output signal, a processingcircuit, for receiving the output signal from the RF antenna anddetermining a magnetic field strength of the magnetic field, a displaydevice coupled to the housing, at least one memory; and at least oneprocessor, coupled to the processing circuit, the display device and theat least one memory, causes the at least one processor to perform amethod comprising: displaying on the display device a map image that isgenerated based on first map data selected by the at least oneprocessor.

Another embodiment is directed to a locate receiver to detect a presenceor an absence of an underground facility. The locate receiver comprises:a housing; an RF antenna for receiving a magnetic field and outputtingan output signal; a processing circuit, for receiving the output signalfrom the RF antenna and determining a magnetic field strength of themagnetic field; a display device coupled to the housing; at least onememory; and at least one processor, coupled to the processing circuit,the display device and the at least one memory, configured to: displayon the display device a map image that is generated based on first mapdata selected by the at least one processor and that includes ageographic location at which an indication of detection of a facilityline was generated; and overlay at least one electronic marking on thefirst map image at a position on the first map image corresponding to alocation at which the indication of detection of a facility line wasgenerated.

Another embodiment is directed to a method for displaying information ona locate receiver having a housing, an RF antenna for receiving amagnetic field and outputting an output signal, a processing circuit,for receiving the output signal from the RF antenna and determining amagnetic field strength of the magnetic field, a display device coupledto the housing, at least one memory; and at least one processor, coupledto the processing circuit, the display device and the at least onememory. The method comprises: displaying on the display device a mapimage that is generated based on first map data selected by the at leastone processor and that includes a geographic location at which anindication of detection of a facility line was generated; and overlayingat least one electronic marking on the first map image at a position onthe first map image corresponding to a location at which the indicationof detection of a facility line was generated.

Another embodiment is directed to at least one computer-readable storagemedium encoded with instructions that, when executed on at least oneprocessor in a locate receiver having a housing, an RF antenna forreceiving a magnetic field and outputting an output signal, a processingcircuit, for receiving the output signal from the RF antenna anddetermining a magnetic field strength of the magnetic field, a displaydevice coupled to the housing, at least one memory; and at least oneprocessor, coupled to the processing circuit, the display device and theat least one memory, causes the at least one processor to perform amethod comprising: displaying on the display device a map image that isgenerated based on first map data selected by the at least one processorand that includes a geographic location at which an indication ofdetection of a facility line was generated; and overlaying at least oneelectronic marking on the first map image at a position on the first mapimage corresponding to a location at which the indication of detectionof a facility line was generated.

Another embodiment is directed to a locate receiver to detect a presenceor an absence of an underground facility. The locate receiver comprises:a housing; an RF antenna for receiving a magnetic field and outputtingan output signal; a processing circuit, for receiving the output signalfrom the RF antenna and determining a magnetic field strength of themagnetic field; a display device coupled to the housing; at least onememory; and at least one processor, coupled to the processing circuit,the display device and the at least one memory, configured to: displayon the display device a map image that is generated based on first mapdata that comprises facilities map data and is selected by the at leastone processor; and compare a location at which an indication ofdetection of a facility was generated to a location of a facility lineas indicated by the first map data and generate an alert based on thecomparison.

Another embodiment is directed to a method for displaying information ona locate receiver having a housing, an RF antenna for receiving amagnetic field and outputting an output signal, a processing circuit,for receiving the output signal from the RF antenna and determining amagnetic field strength of the magnetic field, a display device coupledto the housing, at least one memory; and at least one processor, coupledto the processing circuit, the display device and the at least onememory. The method comprises: displaying on the display device a mapimage that is generated based on first map data that comprisesfacilities map data and is selected by the at least one processor; andcomparing a location at which an indication of detection of a facilitywas generated to a location of a facility line as indicated by the firstmap data and generating an alert based on the comparison.

Another embodiment is directed to at least one computer-readable storagemedium encoded with instructions that, when executed on at least oneprocessor in a locate receiver having a housing, an RF antenna forreceiving a magnetic field and outputting an output signal, a processingcircuit, for receiving the output signal from the RF antenna anddetermining a magnetic field strength of the magnetic field, a displaydevice coupled to the housing, at least one memory; and at least oneprocessor, coupled to the processing circuit, the display device and theat least one memory, causes the at least one processor to perform amethod comprising: displaying on the display device a map image that isgenerated based on first map data that comprises facilities map data andis selected by the at least one processor; and comparing a location atwhich an indication of detection of a facility was generated to alocation of a facility line as indicated by the first map data andgenerating an alert based on the comparison.

For purposes of the present disclosure, the term “dig area” refers to aspecified area of a work site within which there is a plan to disturbthe ground (e.g., excavate, dig holes and/or trenches, bore, etc.), andbeyond which there is no plan to excavate in the immediate surroundings.Thus, the metes and bounds of a dig area are intended to providespecificity as to where some disturbance to the ground is planned at agiven work site. It should be appreciated that a given work site mayinclude multiple dig areas.

The term “facility” refers to one or more lines, cables, fibers,conduits, transmitters, receivers, or other physical objects orstructures capable of or used for carrying, transmitting, receiving,storing, and providing utilities, energy, data, substances, and/orservices, and/or any combination thereof. The term “undergroundfacility” means any facility beneath the surface of the ground. Examplesof facilities include, but are not limited to, oil, gas, water, sewer,power, telephone, data transmission, cable television (TV), and/orinternet services.

The term “locate device” refers to any apparatus and/or device fordetecting and/or inferring the presence or absence of any facility,including without limitation, any underground facility. In variousexamples, a locate device may include both a locate transmitter and alocate receiver (which in some instances may also be referred tocollectively as a “locate instrument set,” or simply “locate set”).

The term “marking device” refers to any apparatus, mechanism, or otherdevice that employs a marking dispenser for causing a marking materialand/or marking object to be dispensed, or any apparatus, mechanism, orother device for electronically indicating (e.g., logging in memory) alocation, such as a location of an underground facility. Additionally,the term “marking dispenser” refers to any apparatus, mechanism, orother device for dispensing and/or otherwise using, separately or incombination, a marking material and/or a marking object. An example of amarking dispenser may include, but is not limited to, a pressurized canof marking paint. The term “marking material” means any material,substance, compound, and/or element, used or which may be usedseparately or in combination to mark, signify, and/or indicate. Examplesof marking materials may include, but are not limited to, paint, chalk,dye, and/or iron. The term “marking object” means any object and/orobjects used or which may be used separately or in combination to mark,signify, and/or indicate. Examples of marking objects may include, butare not limited to, a flag, a dart, and arrow, and/or an RFID markingball. It is contemplated that marking material may include markingobjects. It is further contemplated that the terms “marking materials”or “marking objects” may be used interchangeably in accordance with thepresent disclosure.

The term “locate mark” means any mark, sign, and/or object employed toindicate the presence or absence of any underground facility. Examplesof locate marks may include, but are not limited to, marks made withmarking materials, marking objects, global positioning or otherinformation, and/or any other means. Locate marks may be represented inany form including, without limitation, physical, visible, electronic,and/or any combination thereof.

The terms “actuate” or “trigger” (verb form) are used interchangeably torefer to starting or causing any device, program, system, and/or anycombination thereof to work, operate, and/or function in response tosome type of signal or stimulus. Examples of actuation signals orstimuli may include, but are not limited to, any local or remote,physical, audible, inaudible, visual, non-visual, electronic,mechanical, electromechanical, biomechanical, biosensing or othersignal, instruction, or event. The terms “actuator” or “trigger” (nounform) are used interchangeably to refer to any method or device used togenerate one or more signals or stimuli to cause or causing actuation.Examples of an actuator/trigger may include, but are not limited to, anyform or combination of a lever, switch, program, processor, screen,microphone for capturing audible commands, and/or other device ormethod. An actuator/trigger may also include, but is not limited to, adevice, software, or program that responds to any movement and/orcondition of a user, such as, but not limited to, eye movement, brainactivity, heart rate, other data, and/or the like, and generates one ormore signals or stimuli in response thereto. In the case of a markingdevice or other marking mechanism (e.g., to physically or electronicallymark a facility or other feature), actuation may cause marking materialto be dispensed, as well as various data relating to the markingoperation (e.g., geographic location, time stamps, characteristics ofmaterial dispensed, etc.) to be logged in an electronic file stored inmemory. In the case of a locate device or other locate mechanism (e.g.,to physically locate a facility or other feature), actuation may cause adetected signal strength, signal frequency, depth, or other informationrelating to the locate operation to be logged in an electronic filestored in memory.

The terms “locate and marking operation,” “locate operation,” and“locate” generally are used interchangeably and refer to any activity todetect, infer, and/or mark the presence or absence of an undergroundfacility. In some contexts, the term “locate operation” is used to morespecifically refer to detection of one or more underground facilities,and the term “marking operation” is used to more specifically refer tousing a marking material and/or one or more marking objects to mark apresence or an absence of one or more underground facilities. The term“locate technician” refers to an individual performing a locateoperation. A locate and marking operation often is specified inconnection with a dig area, at least a portion of which may be excavatedor otherwise disturbed during excavation activities.

The term “user” refers to an individual utilizing a locate device and/ora marking device and may include, but is not limited to, land surveyors,locate technicians, and support personnel.

The terms “locate request” and “excavation notice” are usedinterchangeably to refer to any communication to request a locate andmarking operation. The term “locate request ticket” (or simply “ticket”)refers to any communication or instruction to perform a locateoperation. A ticket might specify, for example, the address ordescription of a dig area to be marked, the day and/or time that the digarea is to be marked, and/or whether the user is to mark the excavationarea for certain gas, water, sewer, power, telephone, cable television,and/or some other underground facility. The term “historical ticket”refers to past tickets that have been completed.

The following U.S. published applications and patents are herebyincorporated herein by reference:

-   U.S. Pat. No. 7,640,105, issued Dec. 29, 2009, filed Mar. 13, 2007,    and entitled “Marking System and Method With Location and/or Time    Tracking;”-   U.S. publication no. 2008-0245299-A1, published Oct. 9, 2008, filed    Apr. 4, 2007, and entitled “Marking System and Method;”-   U.S. publication no. 2009-0013928-A1, published Jan. 15, 2009, filed    Sep. 24, 2008, and entitled “Marking System and Method;”-   U.S. publication no. 2009-0238414-A1, published Sep. 24, 2009, filed    Mar. 18, 2008, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0241045-A1, published Sep. 24, 2009, filed    Sep. 26, 2008, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0238415-A1, published Sep. 24, 2009, filed    Sep. 26, 2008, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0241046-A1, published Sep. 24, 2009, filed    Jan. 16, 2009, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0238416-A1, published Sep. 24, 2009, filed    Jan. 16, 2009, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0237408-A1, published Sep. 24, 2009, filed    Jan. 16, 2009, and entitled “Virtual White Lines for Delimiting    Planned Excavation Sites;”-   U.S. publication no. 2009-0202101-A1, published Aug. 13, 2009, filed    Feb. 12, 2008, and entitled “Electronic Manifest of Underground    Facility Locate Marks;”-   U.S. publication no. 2009-0202110-A1, published Aug. 13, 2009, filed    Sep. 11, 2008, and entitled “Electronic Manifest of Underground    Facility Locate Marks;”-   U.S. publication no. 2009-0201311-A1, published Aug. 13, 2009, filed    Jan. 30, 2009, and entitled “Electronic Manifest of Underground    Facility Locate Marks;”-   U.S. publication no. 2009-0202111-A1, published Aug. 13, 2009, filed    Jan. 30, 2009, and entitled “Electronic Manifest of Underground    Facility Locate Marks;”-   U.S. publication no. 2009-0204625-A1, published Aug. 13, 2009, filed    Feb. 5, 2009, and entitled “Electronic Manifest of Underground    Facility Locate Operation;”-   U.S. publication no. 2009-0204466-A1, published Aug. 13, 2009, filed    Sep. 4, 2008, and entitled “Ticket Approval System For and Method of    Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0207019-A1, published Aug. 20, 2009, filed    Apr. 30, 2009, and entitled “Ticket Approval System For and Method    of Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0210284-A1, published Aug. 20, 2009, filed    Apr. 30, 2009, and entitled “Ticket Approval System For and Method    of Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0210297-A1, published Aug. 20, 2009, filed    Apr. 30, 2009, and entitled “Ticket Approval System For and Method    of Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0210298-A1, published Aug. 20, 2009, filed    Apr. 30, 2009, and entitled “Ticket Approval System For and Method    of Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0210285-A1, published Aug. 20, 2009, filed    Apr. 30, 2009, and entitled “Ticket Approval System For and Method    of Performing Quality Control In Field Service Applications;”-   U.S. publication no. 2009-0324815-A1, published Dec. 31, 2009, filed    Apr. 24, 2009, and entitled “Marking Apparatus and Marking Methods    Using Marking Dispenser with Machine-Readable ID Mechanism;”-   U.S. publication no. 2010-0006667-A1, published Jan. 14, 2010, filed    Apr. 24, 2009, and entitled, “Marker Detection Mechanisms for use in    Marking Devices And Methods of Using Same;”-   U.S. publication no. 2009-0204238-A1, published Aug. 13, 2009, filed    Feb. 2, 2009, and entitled “Electronically Controlled Marking    Apparatus and Methods;”-   U.S. publication no. 2009-0208642-A1, published Aug. 20, 2009, filed    Feb. 2, 2009, and entitled “Marking Apparatus and Methods For    Creating an Electronic Record of Marking Operations;”-   U.S. publication no. 2009-0210098-A1, published Aug. 20, 2009, filed    Feb. 2, 2009, and entitled “Marking Apparatus and Methods For    Creating an Electronic Record of Marking Apparatus Operations;”-   U.S. publication no. 2009-0201178-A1, published Aug. 13, 2009, filed    Feb. 2, 2009, and entitled “Methods For Evaluating Operation of    Marking Apparatus;”-   U.S. publication no. 2009-0238417-A1, published Sep. 24, 2009, filed    Feb. 6, 2009, and entitled “Virtual White Lines for Indicating    Planned Excavation Sites on Electronic Images;”-   U.S. publication no. 2009-0202112-A1, published Aug. 13, 2009, filed    Feb. 11, 2009, and entitled “Searchable Electronic Records of    Underground Facility Locate Marking Operations;”-   U.S. publication no. 2009-0204614-A1, published Aug. 13, 2009, filed    Feb. 11, 2009, and entitled “Searchable Electronic Records of    Underground Facility Locate Marking Operations;”-   U.S. publication no. 2009-0327024-A1, published Dec. 31, 2009, filed    Jun. 26, 2009, and entitled “Methods and Apparatus for Quality    Assessment of a Field Service Operation;”-   U.S. publication no. 2010-0010862-A1, published Jan. 14, 2010, filed    Aug. 7, 2009, and entitled, “Methods and Apparatus for Quality    Assessment of a Field Service Operation Based on Geographic    Information;”-   U.S. publication No. 2010-0010863-A1, published Jan. 14, 2010, filed    Aug. 7, 2009, and entitled, “Methods and Apparatus for Quality    Assessment of a Field Service Operation Based on Multiple Scoring    Categories;”-   U.S. publication no. 2010-0010882-A1, published Jan. 14, 2010, filed    Aug. 7, 2009, and entitled, “Methods and Apparatus for Quality    Assessment of a Field Service Operation Based on Dynamic Assessment    Parameters;” and-   U.S. publication no. 2010-0010883-A1, published Jan. 14, 2010, filed    Aug. 7, 2009, and entitled, “Methods and Apparatus for Quality    Assessment of a Field Service Operation Based on Multiple Quality    Assessment Criteria.”

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, allcombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should also be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning most consistentwith the particular concepts disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are not necessarily to scale, emphasis instead generallybeing placed upon illustrating the principles of the invention.

FIG. 1 shows an example in which a locate and marking operation isinitiated as a result of an excavator providing an excavation notice toa one-call center.

FIG. 2 illustrates one example of a conventional locate instrument setincluding a locate transmitter and a locate receiver.

FIGS. 3A and 3B illustrate a conventional marking device in an actuatedand non actuated state, respectively.

FIG. 4 is a functional block diagram of a data acquisition systemincluding a locate device for creating electronic records of locatedoperations and displaying facilities map information, according to someembodiments of the present invention.

FIG. 5 is a perspective view of the data acquisition system of FIG. 4,illustrating an exemplary locate device upon which some embodiments ofthe invention may be implemented.

FIG. 6 illustrates an example of facilities map information that may beviewed on the display of the locate device shown in FIGS. 4 and 5;

FIG. 7 illustrates a sketch representing an exemplary input image thatmay be viewed on the display of the locate device.

FIG. 8 illustrates a map, representing an exemplary input image that maybe viewed on the display of the locate device.

FIG. 9 illustrates a construction/engineering drawing, representing anexemplary input image that may be viewed on the display of the locatedevice.

FIG. 10 illustrates a land survey map, representing an exemplary inputimage that may be viewed on the display of the locate device.

FIG. 11 illustrates a grid, overlaid on the construction/engineeringdrawing of FIG. 9, representing an exemplary input image that may beviewed on the display of the locate device.

FIG. 12 illustrates a street level image, representing an exemplaryinput image that may be viewed on the display of the locate device.

FIG. 13 illustrates an example of a video frame sequence of a facilitiesmap that may be displayed on the display of a locate device, inaccordance with some embodiments.

FIG. 14 illustrates a flow diagram of a process for displaying afacilities map on the display of a locate device, in accordance withsome embodiments.

FIG. 15 illustrates a flow diagram of a process for overlaying data on afacilities map displayed on the display of a locate device.

FIG. 16 shows a display device having a display field in which one ormore display layers and/or sub-layers of locate information, landmarkinformation and/or image/reference information may be selectivelyenabled or disabled for display, according to one embodiment of thepresent invention.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various conceptsrelated to, and embodiments of, inventive systems, methods and apparatusfor viewing facilities maps information and/or other image informationon a locate device. It should be appreciated that various conceptsintroduced above and discussed in greater detail below may beimplemented in any of numerous ways, as the disclosed concepts are notlimited to any particular manner of implementation. Examples of specificimplementations and applications are provided primarily for illustrativepurposes.

Various embodiments of the present invention relate to a locate devicecapable of accessing and displaying various types of information derivedfrom one or more facilities maps. In some embodiments, the locate devicemay have the capability to access one or more locally and/or remotelystored electronic facilities maps or a database of facility mapinformation, and select and display all or a portion of a facilities mapthat is of interest to a technician or other technician of the locatedevice. As explained in detail below, in some embodiments, the locatedevice may update the display of the facilities map information inessentially real-time (e.g., change one or more of pan, zoom,orientation, etc.), as the locate device is in use, when changes in thegeo-location and/or heading of the locate device are detected. In thismanner, the locate device provides a convenient way for the locatetechnician to view and interact with facilities map information inreal-time while conducting a locate and/or marking operation (and/orimmediately before or after the locate operation).

In various aspects, the inventive concepts discussed herein generallyrelate to one of more of the following: 1) selection, from a local orremote library/archive, of one or more appropriate “base” facilitiesmaps or facilities map data sets relating to a given work site/dig area;2) manual or automated selection of an appropriate pan and/or zoom(resolution) for displaying, on a user interface/display of a locatedevice, facilities map information derived from the base facilitiesmap(s); 3) appropriately updating, if/as necessary, displayed facilitiesmap information while a locate device is used during a locate operation;4) overlaying, on the displayed facilities map information, informationrelating to the locate operation; and 5) storing locally on the locatedevice, and/or transmitting from the locate device, facilities mapinformation and/or overlaid locate information (e.g., for furtherprocessing, analysis and/or subsequent display).

Furthermore, in addition to facilities map information, it should beappreciated that the present disclosure contemplates other types ofimage information being accessed and displayed on a userinterface/display of a locate device to facilitate various aspects of alocate and/or marking operation. For example, other types of maps (e.g.,street/road maps, polygon maps, tax maps, etc.), architectural,construction and/or engineering drawings, land surveys, and photographicrenderings/images, and various information derived therefrom, includingvirtual white line (VWL) designations that delimit, on a map or otherimage, a planned excavation area, may be displayed on the locate deviceand may also be used as the basis for overlaying locate informationrelating to a locate operation.

I. Locate Devices

As discussed above a locate device (or so-called “locate set”) mayinclude at least one transmitter and a locate receiver. In oneembodiment of the present invention, one or both of a locate transmitterand a locate receiver may be particularly configured to acquire locateinformation relating to a locate operation, generate an electronicrecord of the acquired locate information, and store, transmit, analyzeor otherwise process the acquired locate information. Such locatedevices also may be configured to access and display facilities mapinformation to facilitate the locate operation.

Various types of locate information may be generated during, orotherwise associated with, the use of a locate set to perform a locateoperation. For example, locate information related to the use of thetransmitter may include, but is not limited to, information about theapplied signal power, the applied signal frequency, the location of thetransmitter, the connection point type (i.e., the manner in whichconnection is made to the target object, such as direct connection,inductive coupling, etc.), an identification of the transmitter unit(e.g., serial number), information about how the transmitter unit isgrounded (if at all), and an indication of whether a sufficientelectrical connection has been made to the target object (e.g., sometransmitters produce a “continuity signal” indicative of the quality ofthe connection between the transmitter and the target object). Locateinformation related to the use of the locate receiver may include, butis not limited to, an identification of the locate receiver (e.g., aserial number), the mode of operation of the locate receiver (e.g., peakmode v. null mode), the frequency to which the locate receiver is tuned,the gain of the locate receiver, the frequency of a detected magneticfield, the amplitude/strength of a detected magnetic field, theelectrical current of the detected signal, the location of the locatereceiver, and a depth measurement taken by the locate receiver (whichmay be used, for example, as additional information regarding a targetobject). In addition, locate information relating to the locateoperation itself may include, but is not limited to, information aboutthe target object, the location of the locate site, the party requestingthe locate, the party performing the locate, and whether any locateoperations have previously been performed for this site.

According to some aspects of the invention, locate information relatingto a locate set, and/or locate operation more generally, may berecorded, transmitted, and/or processed, for example, to enableevaluation of the performance of the locate technician, evaluation ofthe operation of the locate equipment, reconstruction of the actionstaken by the locate technician during the locate operation, and/or tofacilitate comparison of collected data to historical data. In oneexemplary embodiment, a locate receiver is configured to store and/ortransmit locate information relating to a locate set and/or a locateoperation, and in some implementations generate an electronic record ofat least some of the locate information. Examples of locate-relatedinformation that may be logged into an electronic record may include anyof the types of information described above or any suitable combinationsof information of interest, and generally may include, but are notlimited to:

-   -   timing information (e.g., one or more time stamps) associated        with one or more events occurring during a given locate        operation;    -   geographic information (e.g., one or more geographic        coordinates) associated with one or more events of a locate        operation (in some instances, the geographic information may be        accompanied by timing information, such as a time stamp, for        each acquisition of geographic information); and/or geographic        diagnostics information (e.g., GPS diagnostics information, such        as, but not limited to, the quality of a GPS signal, the number        of satellites in view of the GPS receiver, etc.);    -   service-related information: one or more identifiers for the        locate technician performing the locate operation, the locate        contractor (service provider) dispatching the locate technician,        and/or the party requesting the locate operation;    -   ticket information: information relating to one or more        facilities to be located, location information (e.g., an        address, geo-coordinates, and/or text description) relating to        the work site and/or dig area in which the locate and marking        operation is performed, ground type information (e.g., a        description of the ground at which the locate is performed),        excavator information, other text-based information, etc.    -   target object information: information about the target object        (e.g., facility) to be located, such as the type of object,        expected depth of object, etc.;    -   locate performance information: information entered, detected        and/or sensed as part of performing the locate operation, such        as ground type in the area of the locate operation (e.g., grass,        pavement, etc., which could also or alternatively be indicated        in ticket information), magnetic field strength and frequency,        electric current magnitude, depth of the located object, the        mode of operation of the locate receiver (e.g., peak v. null        detection modes), the gain of the locate receiver, etc. With        respect to locate receivers, the “gain” is typically a measure        of the degree of sensitivity of a locate receiver antenna that        is picking up a signal emanating from along an underground        facility (alternatively, “gain” may be viewed as a degree of        amplification being applied to a received signal). Gain may be        expressed in terms of any scale (e.g., 0-100), as a numeric        value or percentage. “Signal strength” (or “magnetic field        strength”) refers to the strength of a received signal at a        given gain value; signal strength similarly may be expressed in        terms of any scale, as a numeric value or percentage. Generally        speaking, higher signal strengths at lower gains typically        indicate more reliable information from a locate receiver, but        this may not necessarily be the case for all locate operations;    -   locate receiver information: information about the locate        receiver, such as identification of the locate receiver (e.g.,        serial number), make and model of the locate receiver, mode of        operation, battery level, etc.; and    -   transmitter information: information about any transmitter and        transmitter signal (also referred to herein as an applied        signal) utilized for the locate operation, such as transmitter        type, connection type, applied signal frequency, transmitter        power, whether a continuity indication is provided for the        applied signal, etc.

One or more electronic records based on the locate information describedabove, or any other locate-related information, may be generated,logged/stored in local memory of the locate receiver, formatted in anyof a variety of manners, saved as any of a variety of file types havingany of a variety of data structures, processed and/or analyzed at thelocate receiver itself, and/or transmitted to another device (forexample, to a computer or, in those embodiments in which multiple locatereceivers are used to complete a same locate operation, to anotherlocate receiver) for storage, processing and/or analysis.

FIGS. 4 and 5 illustrate a functional block diagram and perspectiveview, respectively, of one example of a data acquisition system 100,including a locate device such as a locate receiver 110 and optionally aremote computer 150, according to one embodiment of the presentinvention. One or both of the locate receiver 110 and the remotecomputer 150 of the data acquisition system 100 may be configuredcollect locate information relating to performance of a locateoperation.

As shown in FIG. 4, in one embodiment locate receiver 110 includescontrol electronics 112, the components of which are powered by a powersource 114. Power source 114 may be any power source that is suitablefor use in a portable device, such as, but not limited to, one or morerechargeable batteries, one or more non-rechargeable batteries, a solarphotovoltaic panel, a standard AC power plug feeding an AC-to-DCconverter, and the like.

As also shown in FIG. 4, in one embodiment control electronics 112 oflocate receiver 110 may include, but are not limited to, a processor118, at least a portion of an actuation system 120 (another portion ofwhich may include one or more mechanical elements), a local memory 122,a communication interface 124, a user interface 126, a timing system128, and a location tracking system 130.

The processor 118 may be any general-purpose processor, controller, ormicrocontroller device. Local memory 122 may be any volatile ornon-volatile data storage device, such as, but not limited to, a randomaccess memory (RAM) device and a removable memory device (e.g., auniversal serial bus (USB) flash drive, a multimedia card (MMC), asecure digital card (SD), a compact flash card (CF), etc.). As discussedfurther below, the local memory may store a locate data algorithm 137,which may be a set of processor-executable instructions that whenexecuted by the processor 118 causes the processor to control variousother components of the locate receiver 110 so as to generate anelectronic record 135 of a locate operation, which record also may bestored in the local memory 122 and/or transmitted in essentiallyreal-time (as it is being generated) or after completion of a locateoperation to a remote device (e.g., remote computer 150). In otheraspects, the local memory 122 also may store a map or image viewerapplication 113 (hereafter simply “map viewer application”), and one ormore facilities maps or facilities map data sets 166 and/or other images168. As discussed further below, the one or more facilities maps/datasets 166 may in some implementations include a library of facilitiesmaps, or a database of facilities map data, for one or more differenttypes of facilities deployed in a geographical region.

In one exemplary implementation, a Linux-based processing system forembedded handheld and/or wireless devices may be employed in the locatereceiver 110 to implement various components of the control electronics112. For example; the Fingertip4™ processing system, including a MarvellPXA270 processor and available from InHand Electronics, Inc.(www.inhandelectronics.com/products/fingertip4), may be used. Inaddition to the PXA270 processor (e.g., serving as the processor 118),the Fingertip4™ includes flash memory and SDRAM (e.g., serving as localmemory 122), multiple serial ports, a USB port, and other I/O interfaces(e.g., to facilitate interfacing with one or more input devices andother components of the locate receiver), supports a variety of wiredand wireless interfaces (WiFi, Bluetooth, GPS, Ethernet, any IEEE 802.11interface, or any other suitable wireless interface) to facilitateimplementation of the communication interface 124, and connects to awide variety of LCD displays (to facilitate implementation of a userinterface/display). In yet other exemplary implementations, theprocessor 118 may be realized by multiple processors that divide/sharesome or all of the functionality discussed herein in connection with theprocessor 118. For example, in one implementation, an Atom™ processoravailable from Intel Corporation of Santa Clara, Calif., may be usedalone or in connection with one or more PIC processors to accomplishvarious functionality described herein.

Communication interface 124 of locate receiver 110 may be any wiredand/or wireless communication interface by which information may beexchanged between locate receiver 110 and an external or remote device,such as a remote computing device that is elsewhere in the dig area(i.e., not a part of the locate receiver 110) or outside the dig area.For example, data that is provided by components of data acquisitionsystem 100 and/or stored in local memory 122 (e.g., one or moreelectronic records 135, one or more facilities maps 166) may betransmitted via communication interface 124 to a remote computer, suchas remote computer 150, for processing. Similarly, one or morefacilities maps 166 may be received from the remote computer 150 or oneor more other external sources via the communication interface 124.Examples of wired communication interfaces may include, but are notlimited to, USB ports, RS232 connectors, RJ45 connectors, Ethernet, andany combination thereof. Examples of wireless communication interfacesmay include, but are not limited to, an Intranet connection, Internet,Bluetooth® technology, Wi-Fi, Wi-Max, IEEE 802.11 technology (e.g.,operating at a minimum bandwidth of 54 Mbps, or any other suitablebandwidth), radio frequency (RF), Infrared Data Association (IrDA)compatible protocols, Local Area Networks (LAN), Wide Area Networks(WAN), Shared Wireless Access Protocol (SWAP), any combination thereof,and other types of wireless networking protocols. The wireless interfacemay be capable of capturing signals that reflect a user's intent. Forexample, the wireless interface may include a microphone that cancapture a user's intent by capturing the user's audible commands.Alternatively, the wireless interface may interact with a device thatmonitors a condition of the user, such as eye movement, brain activity,and/or heart rate.

User interface 126 of locate receiver 110 may be any mechanism orcombination of mechanisms by which a user may operate data acquisitionsystem 100 and by which information that is generated by dataacquisition system 100 may be presented to the user. For example, userinterface 126 may include, but is not limited to, a display device(including integrated displays and external displays, such as Heads-UpDisplays (HUDs)), a touch screen, one or more manual pushbuttons, amicrophone to provide for audible commands, one or more light-emittingdiode (LED) indicators, one or more toggle switches, a keypad, an audiooutput (e.g., speaker, buzzer, and alarm), and any combination thereof.In one implementation, the user interface 126 includes a “menu/on”button to power up the locate receiver and provide a menu-drivengraphical user interface (GUI) displayed by the display device (e.g.,menu items and/or icons displayed on the display device) and navigatedby the technician via a joystick or a set of four “up/down/left/right”buttons, as well as a “select/ok” button to take some action pursuant tothe selection of a menu item/icon. As described below, the display mayalso be used in some embodiments of the invention to display informationrelating to one or more facilities maps and/or one or more other imagesgermane to a locate and/or marking information, as well as informationrelating to a placement of marking material in a dig area, a location ofan underground facility in a dig area, or any other suitable informationthat may be displayed based on information acquired to create anelectronic record 135.

In various embodiments, the one or more interfaces of the locatereceiver 110—including the communication interface 124 and userinterface 126—may be used as input devices to receive information to bestored in the memory 122, to facilitate various functions of the locatereceiver and/or to be logged as part of an electronic record of a locateoperation. In some cases, locate information received via theinterface(s) (e.g., via the communication interface 124) may includeticket information regarding underground facilities to be detectedduring a locate operation. As another example, using an interface suchas the user interface 126, service-related information may be input,including an identifier for the locate receiver used by the technician,an identifier for a technician, and/or an identifier for thetechnician's employer. Alternatively, some or all of the service-relatedinformation similarly may be received via the communication interface124 (and likewise some or all of the ticket information may be receivedvia the user interface 126). As also noted above, facilities mapinformation and/or other image information also may be received via thecommunication interface 124.

The actuation system 120 of locate receiver 110 shown in the blockdiagram of FIG. 4 may include both electrical and mechanical elementsaccording to various embodiments discussed in further detail below, andfor purposes of illustration is shown in FIG. 4 as included as part ofthe control electronics 112. The actuation system 120 may include amechanical and/or electrical actuator mechanism (e.g., see the actuator142 shown in FIG. 5) to provide one or more signals or stimuli as aninput to the actuation system 120. Upon receiving one or more signals orstimuli (e.g., actuation/triggering by a locate technician or otheruser), the actuation system 120 may cause the logging of various dataconstituting locate information. To this end, the actuation system 120may provide one or more output signals in the form of an actuationsignal 121 to the processor 118 to indicate one or more actuations ofthe locate receiver, in response to which the processor 118 mayacquire/collect various locate information and log data into theelectronic record 135.

Location tracking system 130 of locate receiver 110 constitutes anothertype of input device that provides locate information, and may includeany device that can determine its geographical location to a certaindegree of accuracy. For example, location tracking system 130 mayinclude a global positioning system (GPS) receiver or a globalnavigation satellite system (GNSS) receiver. A GPS receiver may provide,for example, any standard format data stream, such as a National MarineElectronics Association (NMEA) data stream, or other data formats. Anerror correction component 131 may be, but is not limited to, anymechanism for improving the accuracy of the geographic informationprovided by location tracking system 130; for example, error correctioncomponent 131 may be an algorithm for correcting any offsets (e.g., dueto local disturbances in the atmosphere) in the geo-location data oflocation tracking system 130. While shown as part of a local locationtracking system of the locate receiver 110, error correction component131 alternatively may reside at a remote computing device, such asremote computer 150. In other embodiments, location tracking system 130may include any device or mechanism that may determine location by anyother means, such as performing triangulation by use of cellularradiotelephone towers.

In one exemplary implementation, the location tracking system 130 mayinclude an ISM300F2-C5-V0005 GPS module available from Inventek Systems,LLC of Westford, Mass. (seewww.inventeksys.com/html/ism300f2-c5-v0005.html). The Inventek GPSmodule includes two UARTs (universal asynchronous receiver/transmitter)for communication with the processor 118, supports both the SIRF Binaryand NMEA-0183 protocols (depending on firmware selection), and has aninformation update rate of 5 Hz. A variety of geographic locationinformation may be requested by the processor 118 and provided by theGPS module to the processor 118 including, but not limited to, time(coordinated universal time—UTC), date, latitude, north/south indicator,longitude, east/west indicator, number and identification of satellitesused in the position solution, number and identification of GPSsatellites in view and their elevation, azimuth and SNR values, anddilution of precision values. Accordingly, it should be appreciated thatin some implementations the location tracking system 130 may provide awide variety of geographic information as well as timing information(e.g., one or more time stamps) to the processor 118.

In another embodiment, location tracking system 130 may not residelocally on locate receiver 110. Instead, location tracking system 130may reside on any on-site computer, which serves as a location referencepoint, to which the location of locate receiver 110 may be correlated byany other means, such as, but not limited to, by a triangulationtechnique between the on-site computer and locate receiver 110.

In some embodiments, control electronics 112 may also include one ormore of an electronic compass 160, an inclinometer 170, and one or moreaccelerometers 172. An inclinometer is an instrument for measuringangles of slope (or tilt) or inclination of an object with respect togravity. The inclinometer 170 may be any commercially availableinclinometer device. In one example, inclinometer 170 may be a digitaldevice for sensing the inclination of the locate receiver 110 in whichit is installed (i.e., senses angle of spray). An accelerometer is adevice for measuring acceleration and gravity-induced reaction forces. Amulti-axis accelerometer is able to detect magnitude and direction ofthe acceleration as a vector quantity. The acceleration specificationmay be in terms of g-force, which is a measurement of an object'sacceleration. The accelerometer 172 may be any commercially availableaccelerometer device, including, for example, Part No. ADXL330 sold byAnalog Devices of Wilmington, Mass. In one example, accelerometer 172may be used for detecting the rate of movement of the locate receiver110 in which it is installed. Electronic compass 160 may be anycommercially available electronic compass, including, for example, theOS5000-S sold by OceanServer Technology, Inc. of Fall River, Mass., theSP3002D sold by SPARTON Corporation of Brooksville, Fla., the PNI-PRIMEsold by PNI Sensor Corp. of Santa Rosa, Calif., the Revolution GS soldby True North LLC of Maynard, Mass., or the HMR3400 sold by HoneywellInternational, Inc. of Morristown, N.J.

With respect to other input devices of the locate receiver 110 that mayprovide locate information, the control electronics 112 may also includea timing system 128 having an internal clock (not shown), such as acrystal oscillator device, for processor 118. Additionally, timingsystem 128 may include a mechanism for registering time with a certaindegree of accuracy (e.g., accuracy to the minute, second, ormillisecond) and may also include a mechanism for registering thecalendar date. In various implementations, the timing system 128 may becapable of registering the time and date using its internal clock, oralternatively timing system 128 may receive its time and dateinformation from the location tracking system 130 (e.g., a GPS system)or from an external timing system, such as a remote computer or network,via communication interface 124. In yet other implementations, adedicated timing system for providing timing information to be logged inan electronic record 135 may be optional, and timing information forlogging into an electronic record may be obtained from the locationtracking system 130 (e.g., GPS latitude and longitude coordinates with acorresponding time stamp). Timing information may include, but is notlimited to, a period of time, timestamp information, date, and/orelapsed time.

As shown in FIGS. 4 and 5, the locate receiver 110 further includesdetection electronics 131, which provides another example of an inputdevice that may provide location information to the processor 118. Inexemplary implementations, the detection electronics 131 in turnincludes an RF antenna 127, a detection circuit 139, and a processingcircuit 133. Each of these components is explained in greater detailfurther below.

In one embodiment, information provided by one or more input devices ofthe locate receiver 110 (e.g., the timing system 128, the locationtracking system 130, the detection electronics 131, the user interface126, the communication interface 124) is acquired and logged (stored inmemory) upon actuation of the actuation system 120 (e.g., triggering anactuator). Some embodiments of the invention may additionally oralternatively acquire/log information from one or more input devices atone or more times during or throughout an actuation, such as when atechnician is holding a mechanical or electrical actuator for someperiod of time and moving to detect a presence of an undergroundfacility. In various aspects of such embodiments, locate informationderived from one or more input devices may be collected at a start timeof an actuation, at one or more times during an actuation, and in somecases at regular intervals during an actuation (e.g., several times persecond, once per second, once every few seconds). Further, some locateinformation may be collected at an end of an actuation, such as timeinformation that may indicate a duration of an actuation.

Additionally, it should be appreciated that while some locateinformation may be received via one or more input devices at the startof each locate operation and upon successive actuations of the locatereceiver, in other cases some locate information, as well as facilitiesmaps information and/or other image information, may be collected by orprovided to the locate receiver prior to a locate operation (e.g., onpower-up or reset of the locate receiver, as part of an electronicinstruction or dispatch by a locate company, and/or in response to arequest/query from a locate technician), and stored in local memory 122for subsequent use by the locate receiver (e.g., display of informationvia the user interface display 146, later incorporation into anelectronic record, etc.). For example, prior to a given locate operationand one or more actuations of the locate receiver, one or more of ticketinformation, service-related information, facilities maps information,and other image information, may have already been received (e.g., viathe communication interface 124 and/or user interface 126) and stored inlocal memory 122. Pursuant to a locate operation (e.g., immediatelybefore, during and/or after a locate operation), information previouslyreceived via the interface(s) may be retrieved from the local memory (ifstored there initially), and displayed and/or entered into an electronicrecord as appropriate, in some case together with information collectedpursuant to one or more actuations of the locate receiver. In someimplementations, ticket information and/or service-related informationmay be received via the interface(s) and stored in an entry in theelectronic record 135 “directly” in response to one or more actuationsof the locate receiver (e.g., without being first stored in localmemory).

In sum, according to embodiments of the present invention, variouslocate information from one or more input devices, as well as facilitiesmap information and/or other image information, regardless of how orwhen it is received, may be displayed in various manners and/or storedin memory of the locate receiver (e.g., in an electronic record of alocate operation), and in some implementations at least some of thelocate information may be logged pursuant to one or more actuations ofthe locate receiver.

In various implementations, the optional remoter computer 150 of thedata acquisition system 100 may be any external computer system withwhich the locate receiver 110 communicates (e.g., via the communicationsinterface 124). In one embodiment, the remote computer 150 may be acentralized computer, such as a central server of an undergroundfacility locate service provider. In another embodiment, remote computer150 may be a computer that is at or near the work site (i.e.,“on-site”), e.g., a computer that is present in a locate technician'svehicle. The remote computer may also or alternatively store one or moreof the locate data algorithm 137, the map viewer application 113, one ormore facilities maps 166 (e.g., a library/archive of facilities maps),and one or more images 168. To this end, in some exemplaryimplementations, an example of a remote computer 150 may include animage server or a facilities maps server to provide facilitiesmaps/images to the locate receiver 110.

Whether resident and/or executed on either the locate receiver 110 orthe remote computer 150, as noted above the locate data algorithm 137includes a set of processor-executable instructions (e.g., stored inmemory, such as local memory 122 of the locate receiver) that, whenexecuted by processor 118 of the locate receiver 110 or anotherprocessor, processes information (e.g., various locate information)collected in response to (e.g., during) one or more actuations of thelocate receiver 110, and/or in some cases before or after a givenactuation or series of actuations. Locate data algorithm 137, whenexecuted by the processor 118, may cause the processor to performcollection, logging/storage (creation of electronic records), and insome instances further processing and analysis of various locateinformation with respect to locate receiver actuations.

While the functionality of various components of the locate receiver 110was discussed above in connection with FIG. 4, FIG. 5 shows somestructural aspects of the locate receiver 110 according to oneembodiment. For example, the locate receiver 110 may include anelongated housing 136 in which is disposed one or more elements of theactuation system 120, one or more elements of the control electronics112 and the power source 114. Elongated housing 136 may be hollow or maycontain certain cavities or molded compartments for installing anycomponents therein, such as the various components of locate receiver110 that are shown in FIG. 4. The elongated housing 136 and otherstructural elements associated with the housing, as discussed below, maybe formed of any rigid, semi-rigid, strong, and lightweight material,such as, but not limited to, molded plastic and aluminum.

Incorporated at a proximal end of elongated housing 136 may be a handle138, which provides a convenient grip by which the user (e.g., thelocate technician) may carry the locate receiver 110 during use (i.e.,the exemplary locate receiver depicted in FIG. 5 is intended to be ahand-held device). In one implementation, the power source 114 may beprovided in the form of a removable battery pack housing one or morerechargeable batteries that are connected in series or parallel in orderto provide a DC voltage to locate receiver 110, and disposed within acompartment in the handle 138. Such an arrangement facilitates use ofconventional removable/rechargeable battery packs often employed in avariety of cordless power tools, in which the battery pack similarly issituated in a handle of the tool. It should be appreciated, however,that the power source 114 in the form of a battery pack may be disposedin any of a variety of locations within or coupled to the elongatedhousing 136.

As also shown in FIG. 5, mounted near handle 138 is user interface 126,which may include a display 146. The display 146 may be a touch screendisplay to facilitate interaction with a user/technician, and/or theuser interface also may include one or more buttons, switches,joysticks, a keyboard, and the like to facilitate entry of informationby a user/technician. One or more elements of the control electronics112 (e.g., the processor 118, memory 122, communication interface 124,and timing system 128) also may be located in the proximal end of theelongated housing in the vicinity of the user interface 126 and display146. As with the power source 114, it should be appreciated that one ormore elements of the control electronics 112 may be disposed in any of avariety of locations within or coupled to the elongated housing 136.

In the embodiment of FIG. 5, the location tracking system 130 similarlymay be positioned on the proximal end of the elongated housing 136 tofacilitate substantially unobstructed exposure to the atmosphere; inparticular, as illustrated in FIG. 5, the location tracking system 130may be situated on an a ground plane 133 (providing an electrical groundat least at the antenna frequency of the location tracking system, e.g.,at approximately 1.5 GHz) that extends from the proximal end of thehousing 136 and is approximately parallel to the ground, surface orpavement when the locate receiver is being normally operated by atechnician (so as to reduce signal modulation with subtle movements ofthe locate receiver). As also shown in FIG. 5, incorporated at thedistal end of elongated housing 136 is the detection electronics 131,including RF antenna 127

With respect to the actuation system 120, as shown in FIG. 5, theactuation system 120 includes an actuator 142, which for example may bea mechanical mechanism provided at the handle 138 in the form of atrigger that is pulled by a finger or hand of an user/technician. Inresponse to the signal/stimulus provided by the actuator 142, asdiscussed above the actuation system may provide an actuation signal 121to the processor 118 to indicate an actuation. As discussed in furtherdetail below, pursuant to the execution by the processor 118 of thelocate data algorithm 137, the actuation signal 121 may be used to causethe logging of information that is provided by one or more components ofthe locate receiver 110 so as to generate an electronic record of thelocate operation.

In some embodiments, a user may commence a locate operation with thelocate receiver by inputting various information to the locate receiver,and/or selecting various operating options, via the user interface. As anon-limiting example, the user may select from various menu options(using the user interface and display as a menu-driven GUI), and ormanually enter via the user interface, the type of targetobject/facility to be located, the address of the locate operation, theground type (e.g., grass, pavement, etc.), whether or not a separatetransmitter is being used, the mode of the locate receiver (e.g., Peakv. Null), whether the locate receiver is being operated in landmark modeor not (described further below), or any other information of interestto a locate operation.

In one exemplary implementation, the user may first power on the locatereceiver and log on, for example by entering a user ID. The user maythen navigate through a menu on a touch screen of the user interface toselect the target object to be located, for example selecting from amonga list of options (e.g., including facility types such as gas, sewer,cable, and phone, etc.). Similarly, the user may then navigate through amenu to select the ground type in the area of the locate operation(e.g., selecting from a list of options including grass, pavement, dirt,etc.). The user may then similarly select or input the frequency of anyapplied signal provided by a transmitter, for example using a keypad ofthe user interface or a menu-driven GUI. It should be provided thatthese examples of user actions are non-limiting, and furthermore that insome embodiments one or more of the pieces of information listed may bedetected automatically and not be input/selected by the user.

Once the target object/facility type and any other relevant or desiredinformation is input and/or selected by the technician, and the appliedsignal from the transmitter is coupled to the target object, the locatereceiver may be used in a variety of manners by the technician for alocate operation, in which the technician generally positions (e.g.,sweeps) the locate receiver over an area in which they expect to detectan underground facility. More specifically, the technician positions thelocate receiver such that the RF antenna 127 (which may include morethan one antenna, as described further below) may receive/detect amagnetic field emitted by the target object (see underground facility1515 in FIG. 1A).

In some embodiments, the locate receiver 110 is capable of operating ina null mode (e.g., capable of detecting a null signal when positionedover an object (e.g., facility) emitting a magnetic field), such that RFantenna 127 may comprise a null detection antenna. Alternatively, thelocate receiver 110 is capable of operating in a peak detection mode(e.g., capable of detecting a peak signal when over an object (e.g.,facility) emitting a magnetic field), and the RF antenna 127 comprisestwo peak detection antennae, which may be positioned substantiallyparallel to each other but at different positions within the locatereceiver (e.g., at different heights). In some embodiments, the locatereceiver 110 is capable of operating in both peak detection and nulldetection modes, and the RF antenna 127 may comprise three antennae,e.g., one null detection antenna and two peak detection antennae.However, RF antenna 127 may comprise any other number, type, andorientation of antennae, as the locate receivers described herein arenot limited in these respects.

The RF antenna 127 may be coupled to the detection circuit 139 such thatthe signal(s) received/detected by the RF antenna 127 may be provided tothe detection circuit 139 as an output signal of the RF antenna. Theoutput signal of the RF antenna may be any frequency detectable by theantenna, and in some embodiments may be between approximately 512 Hz and1 MHz, although these non-limiting frequencies are provided primarilyfor purposes of illustration. As mentioned, the output signal of the RFantenna 127, which in some embodiments is an analog signal, may beprovided to detection circuit 139, which may perform various functions.For example, the detection circuit 139 may perform various “front-end”operations on the output signal of RF antenna 127, such as filtering,buffering, frequency shifting or modulation, and/or pre-amplifying theoutput signal. Furthermore, the detection circuit 139 may performadditional functions, such as amplifying and/or digitizing the outputsignal provided by RF antenna 127. It should be appreciated, however,that the types of functions described as being performed by detectioncircuit 139 are non-limiting examples, and that other functions mayadditionally or alternatively be performed.

After detection circuit 139 has operated on the signal from RF antenna127 (e.g., by filtering, buffering, amplifying, and/or digitizing, amongother possible operations), it may provide a signal to processingcircuit 133. The processing circuit 133 may process the signal(s)provided by detection circuit 139 in any suitable manner to determineany information of interest. For example, according to one embodiment,the processing circuit 133 may process the signal(s) from detectioncircuit 139 to determine a magnetic field strength of a magnetic fielddetected by RF antenna 127. The processing circuit 133 may process thesignal(s) from detection circuit 139 to determine an amplitude and/ordirection of the electrical current creating the magnetic field(s)detected by RF antenna 127. Processing circuit 133 may performoperations to calculate, for example, the depth and location of thetarget facility based on the electromagnetic fields detected by RFantenna 127. Processing circuit 133 may be an analog circuit or adigital microprocessor, or any other suitable processing component forperforming one or more of the operations described above, or any otheroperations of interest with respect to signals detected by RE antenna127. Also, it should be appreciated that processing circuit 133 andprocessor 118 may be a single processor in some embodiments, as theillustration of them as distinct in FIG. 4 is only one non-limitingexample.

According to various embodiments, the manner in which locate informationderived from one or more exemplary input devices is logged to localmemory 122 may depend at least in part on the type of data being logged,as the operation of locate receiver 110 is not limited in this respect.

For example, data from timing system 128 and/or location tracking system130 may be automatically logged continuously (e.g., in the form ofstreaming packets with flag fields, as described below, or in any othercontinuous form) or periodically to the local memory 122, may be loggedin response to one or more types of events (e.g., may be loggedautomatically when a particular event occurs), and/or may be logged atany suitable times. In particular, in one implementation, logging mayoccur at periodic intervals during performance of a locate operation,such as every second, every five seconds, every minute, or at any othersuitable time interval. According to another embodiment, timinginformation and/or geographic information from timing system 128 andlocation tracking system 130, respectively, may be logged in response toparticular types of events, such as detecting an underground facility ordetecting the absence of an underground facility. Such events may beidentified by signals output by processing circuit 133 to processor 118.As a non-limiting example, timing information and/or geographicinformation may be logged when a characteristic (e.g., magnetic fieldstrength) of a signal detected by RF antenna 127 is greater than aparticular threshold value, which may be indicated by a signal outputfrom processing circuit 133 to processor 118, and which occurrence maybe indicative of the presence of an underground facility. Similarly, insome embodiments, timing information and/or geographic information maybe logged when a signal detected by RF antenna 127 has a magnitude abovea first threshold and the gain of the locate receiver 110 is above asecond threshold. It should be appreciated that various combinations ofdetected signals detected by locate receiver 110 may be used to triggerlogging of information (e.g., timing information and/or geographicinformation) to local memory. It should also be appreciated that anyinformation available from the location tracking system 130 (e.g., anyinformation available in various NMEA data messages, such as coordinateduniversal time, date, latitude, north/south indicator, longitude,east/west indicator, number and identification of satellites used in theposition solution, number and identification of GPS satellites in viewand their elevation, azimuth and SNR values, dilution of precisionvalues) may be included in geographic information constituting all or aportion of logged locate information.

In some embodiments, information (e.g., timing information and/orgeographic information) may be logged in response to detection of apattern of events, or deviation from a pattern of events. For example, apattern of magnetic field strength magnitudes (e.g., a relativelyconstant magnetic field strength for a given time, an increasingmagnetic field strength, a decreasing magnetic field strength, etc.) maybe detected by the locate receiver, which may trigger logging of timinginformation and/or geographic information. Deviation from a pattern,such as a historical pattern or expected pattern may also triggerlogging of information. For example, a user's historical use patterns ofa locate receiver may be compared to information collected about the useof the locate receiver during a given job, and if a deviation isdetected then logging of timing and/or geographic information may betriggered. The patterns or deviations from patterns may relate topatterns in magnetic field strength, magnetic field frequency, signalgain, user operation, any other information described herein, or anycombination of such information.

In some embodiments, alternatively or in addition to “automatic” loggingof locate information based on some condition or event, a user of thelocate receiver 110 may “manually” trigger logging of timinginformation, geographic information, and/or any other data associatedwith a locate operation or locate receiver (locate information), forexample by manipulating a control (e.g., button, knob, joystick) of theuser interface 126 or, as discussed above, by actuating an actuator 142integrated or otherwise associated with the locate receiver (as shown inFIG. 5), which may be part of the actuation system 120 and which maycause a signal 121 to be sent to the processor 118 to initiate loggingof locate information. For example, according to some embodiments a usermay initiate the locate receiver 110 taking a depth measurement bydepressing a pushbutton of the user interface 126, or pulling/squeezingthe actuator 142, which may also trigger the logging of timinginformation and/or geographic information from timing system 128 andlocation tracking system 130. The depth measurement data, time data,and/or location data may then be logged in an electronic record 135 inlocal memory 122.

It should be appreciated that while the foregoing discussion focuses onlogging locate information to local memory 122, the locate informationmay also, or alternatively, be transmitted to remote computer 150 viacommunication interface 124. As with logging locate information to localmemory 122, the transmission of locate information to remote computer150 may be performed continuously, periodically in response to one ormore types of events, in response to user input or actuation of anactuator, or in any other suitable manner.

In yet other embodiments, the locate receiver 110 may be configured(e.g., via particular instructions executing on the processor 118) tooperate in multiple different modes to collect various informationrelating not only to a locate operation (locate information), butadditionally or alternatively various information relating to the worksite/dig areas in which the locate operation is performed. For example,in one implementation, the locate receiver may be configured to operatein a first “locate mode” which essentially follows various aspects ofthe operation of the locate receiver 110 described herein, and also maybe configured to operate in a second “landmark identification mode.”When switched into the landmark mode, the locate receiver may stopdetecting a magnetic field, e.g., the RF antenna of the locate receivermay be temporarily disabled in some embodiments. In other embodiments,the locate receiver may continue to operate and the landmark mode mayrepresent additional functionality added to the locate receiverfunctionality.

II. Facilities Maps

As noted above and discussed in further detail below, variousembodiments of the present invention relate to accessing and displayingfacilities map information. A facilities map is any physical,electronic, or other representation of the geographic location, type,number, and/or other attributes of a facility or facilities. Facilitiesmaps may be supplied by various facility owners and may indicate thegeographic location of the facility lines (e.g., pipes, cables, and thelike) owned and/or operated by the facility owner. For example,facilities maps may be supplied by the owner of the gas facilities,power facilities, telecommunications facilities, water and sewerfacilities, and so on.

As indicated above, facilities maps may be provided in any of a varietyof different formats. As facilities maps often are provided by facilityowners of a given type of facility, typically a set of facilities mapsincludes a group of maps covering a particular geographic region anddirected to showing a particular type of facility disposed/deployedthroughout the geographic region. One facilities map of such a set ofmaps is sometimes referred to in the relevant arts as a “plat.”

Perhaps the simplest form of facilities maps is a set of paper maps thatcover a particular geographic region. In addition, some facilities mapsmay be provided in electronic form. An electronic facilities map may insome instances simply be an electronic conversion (i.e., a scan) of apaper facilities map that includes no other information (e.g.,electronic information) describing the content of the map, other thanwhat is printed on the paper maps.

Alternatively, however, more sophisticated facilities maps also areavailable which include a variety of electronic information, includinggeographic information and other detailed information, regarding thecontents of various features included in the maps. In particular,facilities maps may be formatted as geographic information system (GIS)map data, in which map features (e.g., facility lines and otherfeatures) are represented as shapes and/or lines, and the metadata thatdescribes the geographic locations and types of map features isassociated with the map features. In some examples, a GIS map data mayindicate a facility line using a straight line (or series of straightlines), and may include some symbol or other annotation (e.g., a diamondshape) at each endpoint of the line to indicate where the line beginsand terminates. From the foregoing, it should be appreciated that insome instances in which the geo-locations of two termination orend-points of a given facility line may be provided by the map, thegeo-location of any point on the facility line may be determined fromthese two end-points.

Examples of a wide variety of environmental landmarks and other featuresthat may be represented in GIS facilities map data include, but are notlimited to: landmarks relating to facilities such as pedestal boxes,utility poles, fire hydrants, manhole covers and the like; one or morearchitectural elements (e.g., buildings); and/or one or more trafficinfrastructure elements (e.g., streets, intersections, curbs, ramps,bridges, tunnels, etc.). GIS facilities map data may also includevarious shapes or symbols indicating different environmental landmarksrelating to facilities, architectural elements, and/or trafficinfrastructure elements.

Examples of information provided by metadata include, but are notlimited to, information about the geo-location of various points along agiven line, the termination points of a given line (e.g., the diamondshapes indicating the start and end of the line), the type of facilityline (e.g., facility type and whether the line is a service line ormain), gee-location of various shapes and/or symbols for other featuresrepresented in the map (environmental landmarks relating to facilities,architectural elements, and/or traffic infrastructure elements), andtype information relating to shapes and/or symbols for such otherfeatures.

The GIS map data and metadata may be stored in any of a variety of ways.For example, in some embodiments, the GIS map data and metadata may beorganized into files, where each file includes the map data and metadatafor a particular geographic region. In other embodiments, the GIS mapdata and metadata may be stored in database and may be indexed in thedatabase by the geographical region to which the map data and metadatacorresponds.

Facilities maps may include additional information that may be useful tofacilitate a locate and/or marking operation. For example, variousinformation that may be included in a legend of the facilities map, orotherwise associated with the facilities map (e.g., included in themetadata or otherwise represented on the map), may include, but is notlimited to, a date of the facilities map (e.g., when the map was firstgenerated/created, and/or additional dates corresponding toupdates/revisions), a number of revisions to the facilities map (e.g.,revision number, which may in some instances be associated with a date),one or more identifiers for a source, creator, owner and/or custodian ofthe facilities map (e.g., the owner of the facility type represented inthe map), various text information (e.g., annotations to update one ormore aspects or elements of the map), and any other legend informationthat may be included or represented in the map.

For facilities maps in electronic form, a variety of digital formats offacilities maps may be used including, but not limited to, a vectorimage format that is the typical output format of computer-aided design(CAD) tools. In one example, some facilities maps may be in a DWG(“drawing”) format, which is a format that used for storing two andthree dimensional design data and metadata, and is a native used byseveral CAD packages including AutoCAD, Intellicad, and PowerCAD.However, those skilled in the art will recognize that facilities mapsmay be in any of several vector and/or raster image formats, such as,but not limited to, DWG, DWF, DGN, PDF, TIFF, MFI, PMF, and JPG.

As noted above, in some instances in which facilities maps are in avector image format, a certain line on the facilities map may berepresented by a starting point geo-location, an ending pointgeo-location, and metadata about the line (e.g., type of line, depth ofline, width of line, distance of line from a reference point (i.e.,tie-down), overhead, underground, line specifications, etc.). Accordingto one embodiment of the present invention as discussed in greaterdetail below, to facilitate display of facilities map informationrelating to multiple different types of facilities, each vector imagemay be assembled in layers, in which respective layers correspond, forexample, to different types of facilities (e.g., gas, water, electric,telecommunications, etc.). In one aspect of such an embodiment, eachlayer is, for example, a set of vector images that are grouped togetherin order to render the representation of the certain type of facility.

FIG. 6 shows an example of a visual representation of a portion of anelectronic facilities map 600. In this example, facilities map 600 is atelecommunications facilities map that is supplied by atelecommunications company. Facilities map 600 shows telecommunicationsfacilities in relation to certain landmarks, such as streets and roads,using lines and shapes. As discussed above, the electronic facilitiesmap may include metadata indicating what various lines, symbols and/orshapes represent, and indicating the geo-location of these lines,symbols and/or shapes. With respect to exemplary environmental landmarksand other features, facilities map 600 may include both visualinformation (graphics and text) and metadata relating to utility poles602, manhole 604, streets 606, and any of a variety of other landmarksand features that may fall within the geographic area covered by thefacilities map 600.

III. Other Types of Image Information

As also noted above and discussed in further detail below, variousembodiments of the present invention relate to accessing and displayingnot only facilities map information but other types of image informationas well and, as with facilities map information, different images can beselected for viewing on a locate device (e.g., the locate receiver 110)at different times, according to various criteria. In some exemplaryimplementations, an “input image” may be stored in local memory 122 ofthe locate receiver and/or retrieved from the optional remote computer150 (e.g., via the communication interface 124) and then stored in localmemory, accessed, and various information may be derived therefrom fordisplay (e.g., all or a portion of the input image, metadata associatedwith the input image, etc.).

For purposes of the present application, an input image is any imagerepresented by source data that is electronically processed (e.g., thesource data is in a computer-readable format) to display the image on adisplay device. An input image may include any of a variety ofpaper/tangible image sources that are scanned (e.g., via an electronicscanner) or otherwise converted so as to create source data (e.g., invarious formats such as XML, PDF, JPG, BMP, etc.) that can be processedto display the input image, including scans of paper facilities maps. Aninput image also may include an image that originates as source data oran electronic file without necessarily having a correspondingpaper/tangible copy of the image (e.g., an image of a “real-world” sceneacquired by a digital still frame or video camera or other imageacquisition device, in which the source data, at least in part,represents pixel information from the image acquisition device).

In some exemplary implementations, input images may be created,provided, and/or processed by a geographic information system (GIS) thatcaptures, stores, analyzes, manages and presents data referring to (orlinked to) location, such that the source data representing the inputimage includes pixel information from an image acquisition device(corresponding to an acquired “real world” scene or representationthereof), and/or spatial/geographic information (“geo-encodedinformation”).

In view of the foregoing, various examples of input images and sourcedata representing input images, to which the inventive conceptsdisclosed herein may be applied, include but are not limited to:

-   -   Manual “free-hand” paper sketches of the geographic area (which        may include one or more buildings, natural or man-made        landmarks, property boundaries, streets/intersections, public        works or facilities such as street lighting, signage, fire        hydrants, mail boxes, parking meters, etc.);    -   Various maps indicating surface features and/or extents of        geographical areas, such as street/road maps, topographical        maps, military maps, parcel maps, tax maps, town and county        planning maps, call-center and/or facility polygon maps, virtual        maps, etc. (such maps may or may not include geo-encoded        information);    -   Architectural, construction and/or engineering drawings and        virtual renditions of a space/geographic area (including “as        built” or post-construction drawings);    -   Land surveys, i.e., plots produced at ground level using        references to known points such as the center line of a street        to plot the metes and bounds and related location data regarding        a building, parcel, utility, roadway, or other object or        installation;    -   A grid (a pattern of horizontal and vertical lines used as a        reference) to provide representational geographic information        (which may be used “as is” for an input image or as an overlay        for an acquired “real world” scene, drawing, map, etc.);    -   “Bare” data representing geo-encoded information (geographical        data points) and not necessarily derived from an        acquired/captured real-world scene (e.g., not pixel information        from a digital camera or other digital image acquisition        device). Such “bare” data may be nonetheless used to construct a        displayed input image, and may be in any of a variety of        computer-readable formats, including XML); and    -   Photographic renderings/images, including street level,        topographical, satellite, and aerial photographic        renderings/images, any of which may be updated periodically to        capture changes in a given geographic area over time (e.g.,        seasonal changes such as foliage density, which may variably        impact the ability to see some aspects of the image).

It should also be appreciated that source data representing an inputimage may be compiled from multiple data/information sources; forexample, any two or more of the examples provided above for input imagesand source data representing input images, or any two or more other datasources, can provide information that can be combined or integrated toform source data that is electronically processed to display an image ona display device.

Various examples of input images as discussed above are provided inFIGS. 7-12. For example, FIG. 7 shows a sketch 1000, representing anexemplary input image; FIG. 8 shows a map 1100, representing anexemplary input image; FIG. 9 shows a construction/engineering drawing1300, representing an exemplary input image; FIG. 10 shows a land surveymap 1400, representing an exemplary input image; FIG. 11 shows a grid1500, overlaid on the construction/engineering drawing 1300 of FIG. 9,representing an exemplary input image; and FIG. 12 shows a street levelimage 1600, representing an exemplary input image.

IV. Displaying Facilities Map Information and/or Other Image Informationon a Locate Device

In some embodiments, locate receiver 110 may display various informationrelating to one or more facilities maps or one or more input images ondisplay 146. For example, processor(s) 118 may access facilities mapdata (e.g., from a file or a database) stored in local memory 122 or mayretrieve facilities map data stored on remote computer 150 and maydisplay on display 146 facilities maps based on the facilities map data.

In some embodiments, processor 118 may execute a map viewer application113 for displaying facilities maps and/or input images. The map viewerapplication 113 may be a custom application or any conventional viewerapplication that is capable of reading in electronic facilities mapsdata or other input images, and rendering all or a portion of theelectronic facilities maps data/input images to an image that can beviewed on display 146. Examples of conventional map viewer applicationssuitable for purposes of some embodiments of the present inventioninclude, but are not limited to, the Bentley® viewer application fromBentley Systems, Inc. (Exton, Pa.) and the ArcGIS viewer applicationfrom Environmental Systems Research Institute (Redlands, Calif.). Whilethe discussion below initially focuses on the display of facilities mapinformation for purposes of illustrating some of the inventive conceptsdisclosed herein, it should be appreciated that the various conceptsdiscussed below apply generally to the display of other types of imageinformation as well.

Processor 118 may select a map to be displayed on display 146 in any ofvariety of ways. In some embodiments, a technician using the locatereceiver may manually select a map to be displayed. For example, thetechnician may access a list of facilities maps available in localmemory 122 and/or stored on remote computer using user interface 126(e.g., via a menu-driven graphics user interface on the user interface126) and may select a desired map from the list. In response, processor118 may access the corresponding map data and render an image of the mapor a portion of the map on display 146 (e.g., using the map viewerapplication 113). The technician may then also adjust the particularportion of the map that is displayed on display 146 by using userinterface 146 to pan or scroll to the desired portion of the map, andmay additionally select the desired zoom level at which the portion ofthe map is displayed.

In some embodiments, processor 118, in addition to or instead ofproviding the capability for a user/technician to manually selectfacilities map information to be displayed on display 146, may alsoautomatically select a facilities map and display all or a portion ofthe selected facilities map on display 146. A variety of techniques maybe used to automatically select a facilities map to be displayed ondisplay 146, as well as a default pan and/or zoom for the selected map,and the invention is not limited to any particular technique.

In some embodiments, a facilities map may be automatically selected fordisplay based, at least in part, on the type of facility being detectedby the locate receiver and/or the current location of the locatereceiver (e.g., obtained from the location tracking system).

For example, in some embodiments, processor 118 may determine the typeof facility being detected by the locate receiver (e.g., using ticketinformation provided via the communications interface 124, orinformation provided by a technician via the user interface 126) andselect a facilities map based on that facility type. Additionally, insome implementations, the locate receive may be in communication with amarking device that provides marking information to the locate receiver,including information regarding the type of facility being marked.Examples of communicatively coupled locate receivers and marking devicesare discussed in U.S. non-provisional application Ser. No. 12/571,397,filed Sep. 30, 2009, entitled “Systems and Methods for GeneratingElectronic Records of Locate and Marking Operations,” which applicationis incorporated herein by reference. As discussed in this application, amarking material detection mechanism of a marking device may determinethe type of facility being marked by determining the color of themarking material loaded into and/or being dispensed by the markingdevice. Because each marking material color corresponds to a particulartype of facility, the color of the marking material may be used toselect a facilities map. Table 1 shows an example of the correspondenceof marking material color to the type of facility to be marked.

TABLE 1 Correspondence of color to facility type Marking material colorFacility Type Red Electric power lines, cables or conduits, and lightingcables Yellow Gas, oil, steam, petroleum, or other hazardous liquid orgaseous materials Orange Communications, cable TV, alarm or signallines, cables, or conduits Blue Water, irrigation, and slurry linesGreen Sewers, storm sewer facilities, or other drain lines WhiteProposed excavation Pink Temporary survey markings Purple Reclaimedwater, irrigation, and slurry lines Black Mark-out for errant lines

Thus, for example, if processor 118 receives a communication from amarking device, in which the marking device has determined from markingmaterial detection mechanism that the color of the marking materialloaded into and/or being dispensed by the marking device is red, thenelectric power lines may be determined as the type of facility beingmarked. As another example, if processor 118 determines from acommunication from a marking device that the color of the markingmaterial loaded into and/or being dispensed by the marking device isyellow, then gas lines may be determined as the type of facility beingmarked.

In other implementations, the processor 118 may prompt, via userinterface 126, the technician using the locate receiver to manuallyinput the type of facility being marked, and may accept the technician'sinput as the type of facility being marked. In yet another embodiment,facility type information may be derived from the ticket information,which typically includes one or more member codes representing facilityowners of different types of facilities. Available ticket informationmay be parsed to determine relevant facility types based on one or moremember codes present in the ticket information (e.g., the locatereceiver, via the communications interface, may receive information fromanother source in which tickets have been parsed to provide facilitytype information; alternatively, tickets themselves may be received viathe communication interface, and the processor 118 may be configured toparse tickets to obtain facility type information). Accordingly, in someimplementations, one or more appropriate facilities maps may beselected, before the locate operation, based on facility typeinformation derived from the ticket information.

In some embodiments, once the type of facility being located has beendetermined, processor 118 may select a facilities map, or facilities mapdata, to render a display on display 146 by determining the currentgeo-location of the locate receiver and selecting a facilities map orfacilities map data corresponding to the facility type being locatedbased on the current location of the locate receiver. Processor 118 maydetermine the current geo-location of the locate receiver from locationtracking system 130 and may select a facilities map or facilities mapdata for the type of facility being detected that includes the currentgeo-location. For example, if the current location of the locatereceiver is 2650.9348,N,08003.5057,W, and the type of facility iselectric power lines, processor 118 may access facilities map data thatcovers an area including 2650.9348,N,08003.5057,W and includes dataindicating the location of electric power lines in this area, and mayrender a map image on display 146 showing the area and location of theelectric power lines in that area.

Other techniques for automatically selecting a facilities map orfacilities map data to render a displayed image may be used. Forexample, in some embodiments, processor 118 may select a facilities mapor facilities map data to be displayed using information from the ticketfor a particular locate operation. For example, an address from theticket may be used to select facilities map data that covers thegeographic area in which the address is located. In some embodiments,one or more member codes from the ticket may be used to determine afacility type that is to be marked and automatically select theappropriate facilities map data for that facility type. For example, ifa ticket includes a member code for the gas company, processor 118 mayautomatically select gas facilities map data. In some situations, aticket may include multiple member codes corresponding to differentutility types. In such situations, standard operating procedure may beused to determine which facilities map to automatically select first.For example, a ticket may include member codes for the gas company andthe electric company. Standard operating procedure may be specify thatgas is to be marked before electric and, as such, processor 118 mayautomatically select the gas facilities map data to be displayed firstand, once the gas locate and marking operation is complete, mayautomatically select the electric facilities map to be displayed next.

In some embodiments, information about the entity that requested thatthe locate operation be performed may be used in automatically selectingfacilities map data. For example, if the electric company requested thatthe locate operation be performed, processor 118 may automaticallyselect the electric facilities map data to be visually rendered anddisplayed.

In addition, in some embodiments, facilities map data may be selectedbased on a virtual white line (VWL) image that includes markings imposedon an image that delimit an area in which excavation is planned. Thus,for example, processor 118 may select facilities map data that includesthe area indicated by the markings.

In some embodiments, once facilities map data has been automaticallyselected, a portion of the facilities map or facilities map data torender an image on display 146 may be identified. That is, thefacilities map data that has been automatically selected may cover anarea significantly larger than the work site/dig area at which a locateand/or marking operation is being conducted, and thus only a portion ofthe selected map data needs to be displayed on display 146. Accordingly,in some embodiments, the map viewer application 113 executing onprocessor 118 may display only a portion of the facilities map data ondisplay 146. The portion of the facilities map to be displayed may beselected in a variety of ways. For example, in some embodiments, atechnician may have the ability to manually select the portion of afacilities map that is desired to be displayed on display 146. As anexample, once a particular facilities map has been automaticallyselected, the facilities map may be displayed on display 146 at adefault zoom level, centered at the current geo-location of the locatereceiver. If the technician desires to a view a different portion of themap or adjust the zoom level, the technician may pan or scroll to adifferent part of the map and adjust the zoom level using the controlsof user interface 126.

In some embodiments, in addition to or instead of providing a technicianwith the capability to manually select a portion of a facilities mapdata to be displayed, processor 118 may automatically select a portionof the facilities map data to be displayed. For example, in someembodiments, processor 118 may select a portion of the selectedfacilities map data to be displayed based on one or more aspects of theticket information pursuant to which the locate and/or marking operationis being performed. In particular, as noted above, the ticketinformation generally includes some description of the work site/digarea (in which excavation, digging or otherwise disturbing the ground isanticipated). While conventionally such information about the worksite/dig area may be included as text comments in the ticketinformation, in some instances the ticket information may include adigital image (e.g., an aerial image) of a geographic areasurrounding/proximate to the work site, on which are placed (e.g., viaan electronic drawing tool) one or more dig area indicators to indicateor delimit a dig area. These marked-up digital images may be savedtogether with metadata pertaining to various information in the images.

An example of a drawing application that may be used to create suchmarked-up images including dig area indicators is described in U.S.patent application Ser. No. 12/366,853 filed Feb. 6, 2009, entitled“Virtual white lines for delimiting planned excavation sites;” U.S.patent application Ser. No. 12/475,905 filed Jun. 1, 2009, entitled“Virtual white lines for delimiting planned excavation sites of stagedexcavation projects;” U.S. patent application Ser. No. 12/422,364 filedApr. 13, 2009, entitled “Virtual white lines (VWL) application forindicating a planned excavation or locate path.” Each of these patentapplications is hereby incorporated by reference herein in its entirety.

In one example, the dig area indicators in a marked-up image may includetwo-dimensional (2D) drawing shapes, shades, points, symbols,coordinates, data sets, or other indicators to indicate on a digitalimage the dig area in which excavation is to occur. To generate theelectronic image having dig area indicators, an image (e.g., an aerialimage) of the work site may be sent to an excavator via a network, theexcavator may use a computing device executing the drawing applicationto create a marked-up image by marking up the image to include one ormore dig area indicators precisely delimiting one or more dig areaswithin the work site and, in response, the marked-up image may bereceived from the excavator via the network.

As noted above, a marked-up image may include metadata corresponding toany markings or content in the image; in particular, geographicinformation including geographic coordinates (e.g., latitude andlongitude values) for any dig area indicators on the marked-up image mayaccompany or be included in an image file as metadata, and thesegeographic coordinates may be employed in a variety of mariners toselect a portion of the facilities map data to be displayed on display146.

For example, in some embodiments, the portion of the facilities map datato be displayed may be selected to include all or a portion of the digarea as indicated on the marked-up image. In particular, in oneexemplary implementation, geographic coordinates associated with asingle dig area indicator may be used to select facilities map contentsthat relates only to a geographic area including the geographiccoordinates for the dig area indicator, or contents that falls within apredetermined radius of the geographic coordinates for the dig areaindicator or a polygon-shaped buffer zone around the geographiccoordinates for the dig area indicator. In yet another example,geographic coordinates associated with multiple dig area indicators thatdelimit a specific dig are may be used to select only contents of thefacilities map that corresponds to the delimited dig area. In yetanother embodiment, the contents of the facilities map that correspondsto the delimited dig area may be displayed with a “buffer frame” aroundthe delimited dig area (e.g., to provide some margins for the viewedsubject matter). Accordingly, it should be appreciated that in someembodiments, the dig area indicator coordinates may identify a pluralityof points along a perimeter of the delimited dig area, and thesecoordinates may be used to select specific geographic information fromthe facilities maps (e.g., filter out geographic information outside ofthe delimited dig area). In other embodiments, the dig area indicatorcoordinates may identify a single point, in which case the coordinatesmay be used to select particular information based at least in part onthe coordinates for the single point.

In some embodiments, the map viewer application 113 executing onprocessor 118 may automatically select an orientation of the map orportion of the map that is displayed on display 146 based on thedirection in which a technician of the locate receiver is moving. Insome conventional techniques for displaying map information, a displayedmap generally is oriented so that north is at the top of the display andsouth is at the bottom of the display. However, the inventors haveappreciated that when displaying a facilities map or portion thereof ona locate receiver during a locate and/or marking operation, orientingthe map such that the direction in which the technician is moving is atthe top of the map may aid the technician in identifying the location ofunderground facilities relative to his or her current position. Thus,for example, if the technician is walking north, then the map viewerapplication may display the selected portion of the map such that northis at the top of the screen. If the technician turns left and is walkingwest, then the map viewer application may re-orient the selected portionof the map such that west is at the top of the screen. In this manner,the map viewer application 113 executing on processor 118 may update theportion and/or the orientation of the facilities map that is beingdisplayed on display 146 in essentially real-time (e.g., update one ormore of pan, zoon, and orientation as the technician moves from oneplace to another during the operation).

The map viewer application 113 may determine the direction in which atechnician is walking using any of a variety of techniques. For example,in some embodiments, processor 118 may monitor the current gee-locationof the locate receiver as indicated by location tracking system 130,determine the direction in which the locate receiver is moving based onchanges in the geo-location, and provide this direction to the mapviewer application. For example, in some embodiments processor 118 maydetermine the direction in which the locate receiver is moving byobtaining the current heading from the electronic compass.

In some embodiments, as noted above, the locate receiver 110 may includeother devices that may be used to determine the direction in which thelocate receiver is moving, such as a compass, an accelerometer, and/oran inclinometer. Thus, in some embodiments, processor 118 may use thesedevices instead of or in addition to location tracking system 130 todetermine the direction in which the locate receiver is moving. Forexample, in some embodiments, the compass may be used to determine aheading in which the locate receiver is moving. In other embodiments,the accelerometer and/or inclinometer may be used to determine thedirection in which the locate receiver is moving.

To demonstrate the concept of automatically orienting and positioning aportion of a facilities map based on technician/device movement andheading, FIG. 13 illustrates an example of a video frame sequence 400that may be displayed on display 146 of locate receiver 110 as atechnician moves the locate receiver to different geo-locations during alocate and/or marking operation. To illustrate video frame sequence 400,FIG. 13 shows an example facilities map 410, which is the facilities mapto be displayed on display 146. Facilities map 410 shows, for example,an intersection 412 of Roosevelt Avenue, which runs east and west, andWalnut Street, which runs north and south. Installed along RooseveltAvenue and/or Walnut Street is a first underground facility 414 and asecond underground facility 416. By way of example, video frame sequence400 shows a frame sequence that is presented on display 146 (e.g., bythe map viewer application 113) to the technician while in the processof locating and/or marking the first underground facility 414. Eachframe of video frame sequence 400 represents a segment of facilities map410 that is being displayed.

Referring to FIG. 13, as the locate technician moves in a northerlydirection along Walnut Street, frame 1 of video frame sequence 400 thatis displayed on display 146 shows underground facility 414 at the southend of Walnut Street with respect to facilities map 410. Additionally,frame 1 is oriented on display 146 with a north heading.

As the locate technician continues to move in a northerly directionalong Walnut Street, frame 2 of video frame sequence 400 that isdisplayed on display 146 shows underground facility 414 whileapproaching intersection 412 of facilities map 410. Additionally, frame2 is still oriented on display 146 with a north heading.

As the locate technician continues to move in a northerly directionthrough intersection 412, frame 3 of video frame sequence 400 that isdisplayed on display 146 shows underground facility 414 at intersection412. Additionally, frame 3 is still oriented on display 114 with a northheading.

As the locate technician changes direction and moves in a westerlydirection along Roosevelt Avenue, frame 4 of video frame sequence 400that is displayed on display 146 shows underground facility 414 whileexiting intersection 412 along Roosevelt Avenue. Additionally, frame 4the orientation of facilities map 410 on display 146 has been updatedfrom a north heading to a west heading.

As the locate technician continues to move in a westerly direction alongRoosevelt Avenue, frame 5 of video frame sequence 400 that is displayedon display 146 shows underground facility 414 at the west end ofRoosevelt Avenue with respect to facilities map 410. Additionally, frame5 is still oriented on display 146 with a west heading.

The inventors have appreciated that, in some situations where the locatetechnician is moving in a particular direction, the locate technicianmay reach a location that is at the end of a the portion of the map thatis currently being displayed, such that if the technician were tocontinue to move along a vector that includes a component in thatdirection, his or her location will no longer be a location on theportion of the map that is currently being displayed, but rather may bea location that is in a different map portion.

Thus, in some embodiments, when a location technician moves from alocation that is on the map portion currently being displayed to alocation that is not on the map portion that is currently beingdisplayed, processor 118 may determine that the technician has moved offthe map portion that is currently being displayed. Processor 118 maythen identify and select additional map data (e.g., stored in the localmemory 122 of the locate receiver, or retrieved from a library/archivestored on remote computer 150) that includes the location to which thetechnician has moved and cause the map viewer application 113 to displaythis other map, in a manner similar to that discussed above inconnection with appropriate selection of maps/images for display.

In addition, in some embodiments, it may be desired to display a mapsuch that the current location of the technician is roughly centered onthe display. In this way, as the technician moves, the portion of themap that is displayed is adjusted so that the geographic location oftechnician on the map is displayed roughly in the center of the display.In such embodiments, the technician may be at a geographic location thatis near or at the end of the currently displayed map portion. Thus, ifthe current location of the technician were to be displayed at roughlythe center of the display, then a portion of the display may be leftblank because the map data that belongs in that portion of the displayis not in the map currently being displayed. Thus, in some embodiments,to address this issue, processor 118 may determine when the technicianis at a location that warrants additional map data to be displayed onthe display at the same time, determine which additional map dataincludes the desired data, stitch together a map image using theadditional map data, and cause this “stitched together” image to bedisplayed on the display.

While the concepts described immediately above (e.g., updating pan, zoomand or orientation of displayed content based on technician/devicemovement and heading) were discussed for purposes of illustration usingfacilities map information, it should be appreciated that the foregoingdiscussion applies similarly to other types of image information (e.g.,from one or more of the input images discussed above in Section III).

FIG. 14 illustrates a flow diagram of a process 500 for selecting andviewing facilities map information or other image information on alocate device, such as locate receiver 110, according to one embodimentof the present invention. Process 500 begins at act 512 where the typeof facility to be detected is established manually or automaticallyusing, for example, any of the techniques discussed above. The processthen continues to act 514, where the location tracking system of thelocate receiver is queried for the current geo-location information. Thegeo-location data from location tracking system 158 may be provided, ina variety of different formats, including for example, in degrees,minutes, and seconds (i.e., DDD° MM′ SS.S″), degrees and decimal minutes(DDD° MM.MMM′), decimal degrees)(DDD.DDDDD°, and/or any combinationthereof.

The process next continue to act 516, where facilities map data thatmatches the determined facility type determined in act 512 and thegeo-location determined in act 514 is identified. The process thencontinues to act 518, where the map viewer application reads in theidentified facilities map data, preparing to present an image of thisfacilities map on the display of the locate receiver. The processor thencontinues to act 520, where the current heading (i.e., the direction inwhich the locate receiver is moving) is determined from, for example,the location tracking system, compass, inclinometer, and/oraccelerometer. Once the current heading is determined, the processcontinues to act 522, where a map or map image segment is orientedaccording to the determined heading and centered according to thecurrent geo-location of the locate receiver, and the facilities mapimage is presented on the display of the locate receiver.

In some embodiments, the locate receiver may alert the technician whenhe or she is at a location of a facility line, as indicated by thefacilities map data. Thus, in some embodiments, the process may continueto act 524, where an alert to the locate technician may be generatedbased on comparing current geo-location of the locate receiver to thegeo-location of the facilities of the displayed facilities map. Inparticular, in one exemplary implementation, the geo-location of thefacilities of the displayed facilities map constitutes “referenceinformation,” to which “field information” in the form of thegeo-location of the locate receiver may be compared. Various methods andapparatus for comparing field information in the context of locate andmarking operations to reference information derived from facilities mapsis discussed in U.S. application Ser. No. 12/571,356, filed Sep. 30,2009, and entitled, “Method And Apparatus For Analyzing Locate AndMarking Operations With Respect To Facilities Maps,” which isincorporated herein by reference in its entirety.

In one example, processor 118 may compare the geo-location data oflocation tracking system 130 to the geo-location information in thedisplayed facilities map. When the two geo-locations substantially match(within a certain acceptable tolerance), an audible indicator, such as abuzzer or alarm may be activated, a tactile indicator such as a devicethat vibrates the handle of the locate receiver, and/or a visualindicator, such as an LED of user interface 126, may be activated inorder to alert the locate technician that he or she is at or near thelocation of the target facility to be detected.

In other embodiments, if the location of the locate receiver differsfrom the location at which the facilities map(s) indicate the facilityline to be detected is located by at least a threshold distance (e.g.six feet or any other suitable threshold distance), processor 118 maycause an alert (e.g., an audible indicator, a tactile indicator, and/ora visual indicator) to the technician to be activated. In addition, anydiscrepancies between the locations at which location information islogged and the locations of the facility lines to be detected asindicated on the facilities map may be logged and later evaluated todetermine whether the discrepancy is a result of facilities mapinaccuracy or locate technician error.

As shown in FIG. 14, the acts of process 500 may repeat any number oftimes and at any programmed frequency (e.g., every 100 milliseconds)until the locate operation is complete. With each iteration of the actsof process 500, the map viewer application updates (or refreshes) thedisplay with the current facilities map information in order to reflectany changing geo-location and/or heading of the locate receiver as thetechnician performs the locate operation.

IV. Overlay of Locate Information on Displayed Facilities MapInformation or Other Image Information

The inventors have appreciated that, as a technician using a locatereceiver detects one or more underground facilities during a locateoperation, it may be useful to overlay, on displayed facilities mapinformation or other displayed image information, electronic marks(“electronic detection marks”) that indicate where thefacility/facilities were detected. This provides the locate technicianwith a visual representation of where facilities were detected by thelocate receiver relative to the location of facility lines shown on thefacilities map. In addition, in some situations, it may be desirable tooverlay one or more indicators, such as a “you are here” icon or apointer icon on the displayed facilities map or other image information,to provide the technician with a visual representation of his or hercurrent location on the displayed portion of the map.

FIG. 15 is an example of a process that may be used to overlay data,such as electronic detection marks indicative of geo-locations at whichunderground facilities were detected via a locate receiver, a presentlocation indicator or a “you are here” icon indicative of the currentlocation of the locate receiver, or any other type of data, on displayedfacilities map information or other image information, according to oneembodiment of the present invention.

The process of FIG. 15 begins at act 901, where the geo-location data ofthe locate information to be overlaid (e.g., geo-location datacorresponding to a detected facility, or current location mark) isdetermined/collected. For example, if the information to be overlaid isa current location mark or “you are here” icon indicative of the currentlocation of the locate receiver, the current location of the locationreceiver may be determined from location tracking system 130. If theinformation to be overlaid is an electronic detection mark indicative ofa geo-location at which a facility is detected, the geo-location datamay be collected from the location tracking system 130 (e.g., inresponse to actuation of the locate receiver, or automatic logging oflocation information) and/or determined, for example, from theelectronic record 135 generated and stored by the locate receiver. Thatis, as discussed above, in some embodiments, each time the locatereceiver 110 is actuated, or characteristics of the magnetic field meetor exceed certain thresholds, the location tracking system may be polledto provide one or more geo-location data points that may be overlaid ondisplayed facilities map information or other image information as anelectronic detection mark, essentially in real-time as the data iscollected; additionally or alternatively, the geo-location data may belogged as data event entries in the electronic record 135 and theelectronic record 135 may be accessed thereafter to obtain geo-locationdata for overlaying on displayed facilities map or other imageinformation one or more electronic detection marks.

Table 2, shown below, lists an example of the contents of an electronicrecord of locate information that may be generated and stored and/ortransmitted relating to operation of a locate receiver, according to onenon-limiting embodiment. The electronic record shown in Table 2 includesa record number (record #1001), an identification of the serviceprovider, an identification of the user (i.e., the locate technicianoperating the locate receiver), and an identification of the locatereceiver. The mode of operation of the locate receiver (e.g., peak) mayalso be included. Timing information (timestamp data) from a timingsystem of the locate receiver and geographic information from a locationtracking system of the locate receiver may also be included. The signalstrength and signal frequency entries of the electronic record indicatecharacteristics of a signal (e.g., a magnetic field) detected by thelocate receiver, for example emitted from an underground facility. Thesignal strength is listed in the example of Table 2 as a percentage ofthe maximum detectable by the locate receiver, although it should beappreciated that other units of measurement may alternatively be used.The gain entry indicates the gain setting of the locate receiver. Theelectronic record also includes an entry for the depth of the facilitytargeted, as may be determined by taking a depth measurement using alocate receiver (e.g., by calculating a difference in magnetic fieldstrength detected by two different antennae at two different locationswithin a locate receiver), and for the facility type (e.g., gas,electric, etc.) and ground type in the area of the locate operation. Theelectronic record of Table 2 also includes the address of the locateoperation and the party requesting the locate operation. Lastly, Table 2includes information about the remaining battery life of the locatereceiver for those embodiments that include a battery.

TABLE 2 Example Electronic Record For Locate Receiver Record Serviceprovider ID 0482 # 1001 User ID 4815 Receiver ID 7362 Receiver modeMode=Peak Timestamp data 12-Jul-2008; 09:35:15 Geo-location data2650.9348,N,08003.5057,W Signal strength (% of 85% maximum) Gain 45Signal frequency 1 kHz Facility depth 3.4 meters Facility type Gas(yellow) Ground type Pavement Battery strength data 85% Locate requestdata Requestor=XYZ Construction Company, Requested service address=222Main St, Orlando, FL

It should be appreciated that Table 2 represents only one non-limitingexample of an electronic record of locate information which may begenerated in accordance with the operation of a locate receiver,according to one embodiment. In particular, a single electronic recordof locate information collected in connection with operation of a locatereceiver may include multiple entries of a given data type. For example,while Table 2 illustrates an electronic record including a single GPSdata point, it should be appreciated that multiple GPS data points maybe taken and stored within a single electronic record. The multiple GPSdata points may be taken in response to a single actuation event (e.g.,single actuator pull by a technician), in response to multiple actuationevents (e.g., multiple actuator pulls by a technician), automaticlogging of data (e.g., based on magnetic field strength), or in othermanners. Thus, multiple pieces of data may be collected for anelectronic record of a locate operation, and it should be appreciatedthat any single electronic record may include multiple entries.

Thus, the geo-location(s) at which one or more facilities are detectedmay be obtained from these electronic records, and/or may be collectedessentially in real-time as the locate operation is being performed.Once the geo-location data to be overlaid on the displayed informationis determined, the process continues to optional act 903, where thisgee-location data may be converted, if necessary, to the spatialreference frame used by the facilities map (or other image) from whichthe information displayed on the display 146 is derived.

As known in the relevant art, a geographic or “global” coordinate system(i.e., a coordinate system in which geographic locations on Earth areidentified by a latitude and a longitude value, e.g., (LAT,LON)) may beused to identify geographic locations of detected facilities and afacility line indicated in facilities map information. In a “geocentric”global coordinate system (i.e., a coordinate system in which the Earthis modeled as a sphere), latitude is defined as the angle from a pointon the surface of a sphere to the equatorial plane of the sphere,whereas longitude is defined as the angle east or west of a referencemeridian between two geographical poles of the sphere to anothermeridian that passes through an arbitrary point on the surface of thesphere. Thus, in a geocentric coordinate system, the center of the Earthserves as a reference point that is the origin of the coordinate system.However, in actuality the Earth is not perfectly spherical, as it iscompressed towards the center at the poles. Consequently, using ageocentric coordinate system can result in inaccuracies.

In view of the foregoing, the Earth is typically modeled as an ellipsoidfor purposes of establishing a global coordinate system. The shape ofthe ellipsoid that is used to model the Earth and the way that theellipsoid is fitted to the geoid of the Earth is called a “geodeticdatum.” In a “geodetic” global coordinate system, the latitude of apoint on the surface of the ellipsoid is defined as the angle from theequatorial plane to a line normal to the reference ellipsoid passingthrough the point, whereas the longitude of a point is defined as theangle between a reference plane perpendicular to the equatorial planeand a plane perpendicular to the equatorial plane that passes throughthe point. Thus, geodetic latitude and longitude of a particular pointdepends on the geodetic datum used.

A number of different geodetic global coordinate systems exist that usedifferent geodetic datums, examples of which include WGS84, NAD83,NAD27, OSGB36, and ED50. As such, a geographic point on the surface ofEarth may have a different latitude and longitude values in differentcoordinate systems. For example, a stop sign at the corner Maple St. andMain St. may have a latitude and longitude of (LAT₁, LON₁) in the WGS84coordinate system, but may have a latitude and longitude of (LAT₂, LON₂)in the NAD83 coordinate system (where LAT₁≠LAT₂ and/or LON₁≠LON₂). Thus,when comparing one geographic point to another geographic point todetermine the distance between them, it is desirable to have bothgeographic points in the same global coordinate system.

Additionally, when determining a geographic location based oninformation derived from a map (e.g., a facilities map), the coordinatesystem provided by the map may not be a global coordinate system, butrather may be a “projected” coordinate system. As appreciated in therelevant art, representing the curved surface of the Earth on a flatsurface or plane is known as a “map projection.” Representing a curvedsurface in two dimensions causes distortion in shape, area, distance,and/or direction. Different map projections cause different types ofdistortions. For example, a projection could maintain the area of afeature but alter its shape. A map projection defines a relation betweenspherical coordinates on the globe (i.e., longitude and latitude in aglobal coordinate system) and flat planar x,y coordinates (i.e., ahorizontal and vertical distance from a point of origin) in a projectedcoordinate system. A facilities map may provide geographic locationinformation in one of several possible projected coordinate systems.

Thus, to overlay geo-location data (e.g., obtained from the locationtracking system 130 of the locate receiver) on displayed facilities mapinformation (or other image information), it is desirable to have thegeo-location data and the facilities map information represented in thesame geodetic global coordinate system or projected coordinate system(projected from the same geodetic geographical coordinate system). Forexample, in some embodiments, the geo-location data points obtained bythe location tracking system of the locate receiver may be provided asgeo-location data in the WGS84 coordinate system (i.e., the coordinatesystem typically used by GPS equipment), whereas the facilities mapinformation may be expressed in the NAD83 coordinate system. Thus, atact 903, the geo-location data coordinates provided by the locationtracking system of the locate receiver may be converted to the NAD83coordinate system so that they may be appropriately overlaid on thedisplayed facilities map information.

The process next continues to act 905, where the data, converted if/asappropriate, may be overlaid on the information displayed on display146, such that display 146 displays both the facilities map/imageinformation and the overlaid data. For example, if the techniciandetected an underground facility at 2650.9273,N,08003.5193,W (decimaldegrees) in the coordinate system used by the facilities map, anelectronic detection mark may be overlaid on the displayed facilitiesmap at the portion of the facilities map that corresponds to2650.9273,N,08003.5193,W. Similarly, if the current location of thelocate receiver is 2680.5243,N,08043.4193,W in the coordinate systemused by the facilities map, then a “you are here” icon may be overlaidon the displayed facilities map at the portion of the facilities mapthat corresponds to 2680.5243,N,08043.4193,W.

Any one of a number of different techniques may be used to overlay dataon the displayed facilities map or image. In some embodiments, the datato be visually rendered on the facilities map or image is mapped to adisplay field of the display device to ensure that the geo-location datafor the data to be overlaid is displayed over the proper place on thedisplayed facilities map or image. For example, in one exemplaryimplementation, a transformation may be derived using informationrelating to the available display field (e.g., a reference coordinatesystem using an appropriate scale for a given display field of a displaydevice) to map data points in the geo-location data for the data to beoverlaid to the available display field. Once such a transformation isderived, the data to be overlaid may be rendered in the display field byapplying the transformation to the geo-location data for the data to beoverlaid.

In the illustrative processes of FIGS. 14 and 15, a separate facilitiesmap may be selected for each facility type (or facility company).However, in some embodiments, rather than using a separate facilitiesmap for each facility type or facility company, an aggregated facilitiesmap or facilities map database may be generated by combining data frommultiple facilities maps, and data from the aggregated facilities mapdatabase may be selected and displayed on the display of the locatereceiver. For example, if gas lines, water lines, and power lines are tobe detected during a locate and/or marking operation in a particularlocation, an aggregated facilities map database may be generated byaccessing the facilities map from the gas company for the location, thefacilities map from the water company for the location, and thefacilities map from the electric company from the location, extractinginformation about the location of map features (e.g., facility lines,streets, and/or other map features) from each of these facilities maps,converting the locations to a common frame of reference (e.g., using thetechniques discussed above), and combining the extracted features into adatabase (e.g., from which a single aggregated map may be derived).Thus, rather than performing the process of FIG. 14 or 15 three timeswith three separate facilities maps (i.e., once using the gas facilitiesmap, once using the water facilities map, and once using the electricfacilities map), the aggregated facilities map may be used each time.

As with a facilities map for a single type of facility, in someembodiments, an electronic representation of underground facilitieslocations detected by a locate receiver (one or more electronicdetection marks), an electronic representation of the current locationof the technician (e.g., a you are here icon), or other information maybe generated and rendered visually (i.e., overlaid) on the aggregatedfacilities map.

In some embodiments, the map or image data and the data to be overlaid(e.g., the electronic representation of underground facilities locationsdetected by a locate receiver or the electronic representation of thecurrent location of the technician), may be displayed as separate“layers” of the visual rendering, such that a viewer of the visualrendering may turn on and turn off displayed data based on acategorization of the displayed data. For example, all facilities map orimage data may be categorized generally under one layer designation(e.g., “Reference”), and independently enabled or disabled for display(e.g., hidden) accordingly. Similarly, all overlaid data may becategorized generally under another layer designation (e.g., “Field”)and independently enabled or disabled for display accordingly.Respective layers may be enabled or disabled for display in any of avariety of manners; for example, in one implementation, a “layerdirectory” or “layer legend” pane may be included in the display field(or as a separate window selectable from the display field of the visualrendering), showing all available layers, and allowing a viewer toselect each available layer to be either displayed or hidden, thusfacilitating comparative viewing of layers.

Furthermore, any of the above-mentioned general categories for layersmay have sub-categories for sub-layers, such that each sub-layer mayalso be selectively enabled or disabled for viewing by a viewer. Forexample, under the general layer designation of “Field,” differentfacility types that may have been detected (and indicated in the fielddata by utility type/color, for example) may be categorized underdifferent sub-layer designations (e.g., “Field—Electric;” “Field—Gas;”etc.); in this manner, a viewer may be able to hide the electric fielddata while viewing the gas field data, or vice versa, in addition tohaving the option to view or hide all field data.

In some embodiments, a variety of other sub-layers may be used. Forexample, sub-layers may be provided for certain types of map metadata.In one example, landmarks (e.g., poles, pedestals, curbs, hydrants,street lights, and/or other types of landmarks) may be a separatesub-layer that can be toggled on and off from the display. In anotherexample, sub-layers for a particular facility type may be provided. Asone example, within the sub-layer “Field—Electric,” a sub-layer may beprovided for aerial electric lines, and another sub-layer may beprovided for underground electric lines. As another example, for asub-layer for telephone lines (e.g, “Field—Telephone”), sub-layers maybe provided for the type of material used. For example, one sub-layermay be provided for copper telephone lines, while another sub-layer maybe provided for fiber lines.

Similarly, in embodiments in which an aggregated facilities map isdisplayed on the display device, the “Reference” layer may havesub-layers for each facility type in the aggregated facilities map. Thatis, each facility type in the aggregated facilities map may have adifferent sub-layer designation, such that a viewer may be able toindividually select which sub-layers are displayed on the displaydevice. For example, if an aggregated facilities map includesinformation from a gas facilities map, an electric facilities map, and acable TV (CATV) facilities map, the data from the gas facilities map,the data from the electric facilities map, and the data from the CATVfacilities may each be a separate sub-layer. As such, the viewer may beable to select which of these layers he or she wishes to be displayed onthe display, and which he or she wishes to be hidden. Virtually anycharacteristic of the information available for display may serve tocategorize the information for purposes of displaying layers orsub-layers.

FIG. 16 shows a generic display device 3000 having a display field 3005with exemplary content for purposes of explaining some concepts germaneto display layers, according to one embodiment. For example, all locateinformation may be categorized generally under one layer designation3030 (“locate layer”) and independently enabled or disabled for displayaccordingly, all landmark information may be categorized generally underyet another layer designation 3040 (“landmark layer”) and independentlyenabled or disabled for display accordingly, and all referenceinformation may be categorized generally under yet another layerdesignation 3050 (“reference layer”) and independent enabled or disabledfor display. Respective layers may be enabled or disabled for display inany of a variety of manners; for example, in one implementation, a“layer directory” or “layer legend” pane 3010 may be included in thedisplay field 3005 (or as a separate window selectable from the displayfield of the visual rendering), showing all available layers, andallowing a viewer to select each available layer to be either displayedor hidden, thus facilitating comparative viewing of layers.

Furthermore, any of the above-mentioned general categories for layersmay have sub-categories for sub-layers, such that each sub-layer mayalso be selectively enabled or disabled for viewing by a viewer. Forexample, under the general layer designation of “locate layer,”different facility types that may have been detected during a locateand/or marking operation (and indicated in the locate information bycolor, for example) may be categorized under different sub-layerdesignations (e.g., designation 3032 for “locate layer—electric;”designation 3034 for “locate layer—gas;” etc.); in this manner, a viewermay be able to hide only the electric locate information while viewingthe gas locate information, or vice versa, in addition to having theoption to view or hide all locate information. Under the layerdesignation of “landmark layer” different types of landmarks may becategorized under different sub-layer designations (e.g., designation3042 for water/sewer landmarks, designation 3044 for cable TV landmarks,and designation 3045 for buildings). Under the layer designation of“reference layer” different types of reference information may becategorized under different sub-layer designations (e.g., designation3052 for base map information, designation 3054 for dig area indicators,designation 3056 for facility lines).

As shown in the example of FIG. 16, of the locate, landmark, andreference layers, only the electric sub-layer of the locate layer andthe buildings sub-layer of the landmark layer are enabled for display.Accordingly, in FIG. 16, only the electronic detection marks 1010indicating where a power line was detected and building 950 appear inthe electronic rendering 1000A shown in FIG. 16.

Virtually any characteristic of the information available for displaymay serve to categorize the information for purposes of displayinglayers or sub-layers. In particular, with respect to informationobtained during performance of a locate and/or marking operation, any ofa variety of exemplary constituent elements of such information (e.g.,timing information, geographic information, service-related information,ticket information, facility type information) may be categorized as asub-layer, and one or more sub-layers may further be categorized intoconstituent elements for selective display (e.g., as sub-sub-layers).For example, timing information may be used to categorize the locateinformation based on a time at which a particular facility line wasdetected, such that one sub-layer may include an electronicrepresentation of the locations at which a facility line was detectedduring a particular time window. Geographic information may be used tocategorize the locate information based on a location at which afacility line was detected, so that one sub-layer may include electronicrepresentations of the locations at which facility lines were detectedfor a particular geographic area.

Service-related information may include, for example, a service-provideridentifier indicative of a service-provider overseeing the locate and/ormarking operation, a technician identifier representing a technicianthat performs the locate operation and/or the marking operation, adevice identifier representing a device used by the technician duringthe locate operation and/or the marking operation, and a statusidentifier representing an operating status of the at least one device.Any such service-related information may be used to categorize thelocate information into one or more sub-layers.

Ticket information may include a ticket number identifying the ticket, aparty identifier representing a party requesting the locate and/or themarking operation, a facility identifier representing a type and/ornumber of one or more facilities to be detected and/or marked in thelocate and/or the marking operation, and/or a ground type identifierrepresenting a ground type for a work site and/or dig area at which thelocate and/or the marking operation is performed. Any such ticketinformation may be used to categorize the marking information into oneor more sub-layers.

Similarly, with respect to the “Reference” layer, virtually anycharacteristic of the information available for display in this layermay serve to categorize the information for purposes of displayingsub-layers. For example, landmarks, particular types of landmarks,particular types of facility lines, dig area indicators (e.g., virtualwhite lines), facility lines owned by a particular entity, and/orfacility lines in a particular geographic area may each be a separatesub-layer.

In some embodiments, processor 118 may automatically select whichsub-layers in the “Reference” layer and/or the “Field” layer aredisplayed. For example, in some embodiments, processor 118 mayautomatically select particular sub-layers to be displayed based on thetype of facility being located. As discussed above, processor 118 maydetermine the type of facility being located in a variety of ways,including for example, based on user input identifying the type offacility being located. Thus, on this basis, processor 118 mayautomatically select certain sub-layers to be displayed and may selectcertain other sub-layers to not be displayed. For example, if atechnician indicates that electric lines are being detected, processor118 may automatically select sub-layers related to electric lines to bedisplayed, and may select sub-layers not related to electric lines tonot be displayed.

In general, it should be appreciated that any constituent element ofinformation from the field (e.g., locate information and/or landmarkinformation) may be used as a basis for automatically selecting/enablingfor display one or more sub-layers of reference/image information. Forexample, if landmark information indicates that acquired landmarkgeo-location data is associated with a hydrant, a “water facilities”sub-layer and/or a “water landmarks” sub-layer may be automaticallyselected from the “Reference” layer for display in the display field.Similarly, if locate information indicates that a gas main is beingdetected, a “gas facilities” sub-layer and/or a “gas landmarks”sub-layer may be automatically selected from the “Reference” layer fordisplay in the display field. The foregoing are merely illustrativeexamples of automatic selection/enabling of Reference sub-layers, andthe inventive concepts discussed herein are not limited in theserespects.

V. Conclusion

While various inventive embodiments have been described and illustratedherein, those of ordinary skill in the art will readily envision avariety of other means and/or structures for performing the functionand/or obtaining the results and/or one or more of the advantagesdescribed herein, and each of such variations and/or modifications isdeemed to be within the scope of the inventive embodiments describedherein. More generally, those skilled in the art will readily appreciatethat all parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the inventive teachingsis/are used. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific inventive embodiments described herein. It is,therefore, to be understood that the foregoing embodiments are presentedby way of example only and that, within the scope of the appended claimsand equivalents thereto, inventive embodiments may be practicedotherwise than as specifically described and claimed. Inventiveembodiments of the present disclosure are directed to each individualfeature, system, article, material, kit, and/or method described herein.In addition, any combination of two or more such features, systems,articles, materials, kits, and/or methods, if such features, systems,articles, materials, kits, and/or methods are not mutually inconsistent,is included within the inventive scope of the present disclosure.

The above-described embodiments can be implemented in any of numerousways. For example, the embodiments may be implemented using hardware,software or a combination thereof. When implemented in software, thesoftware code can be executed on any suitable processor or collection ofprocessors, whether provided in a single computer or distributed amongmultiple computers.

Further, it should be appreciated that a computer may be embodied in anyof a number of forms, such as a rack-mounted computer, a desktopcomputer, a laptop computer, or a tablet computer. Additionally, acomputer may be embedded in a device not generally regarded as acomputer but with suitable processing capabilities, including a PersonalDigital Assistant (PDA), a smart phone or any other suitable portable orfixed electronic device.

Also, a computer may have one or more input and output devices. Thesedevices can be used, among other things, to present a user interface.Examples of output devices that can be used to provide a user interfaceinclude printers or display screens for visual presentation of outputand speakers or other sound generating devices for audible presentationof output. Examples of input devices that can be used for a userinterface include keyboards, and pointing devices, such as mice, touchpads, and digitizing tablets. As another example, a computer may receiveinput information through speech recognition or in other audible format.

Such computers may be interconnected by one or more networks in anysuitable form, including a local area network or a wide area network,such as an enterprise network, and intelligent network (IN) or theInternet. Such networks may be based on any suitable technology and mayoperate according to any suitable protocol and may include wirelessnetworks, wired networks or fiber optic networks.

The various methods or processes outlined herein may be coded assoftware that is executable on one or more processors that employ anyone of a variety of operating systems or platforms. Additionally, suchsoftware may be written using any of a number of suitable programminglanguages and/or programming or scripting tools, and also may becompiled as executable machine language code or intermediate code thatis executed on a framework or virtual machine.

In this respect, various inventive concepts may be embodied as acomputer readable storage medium (or multiple computer readable storagemedia) (e.g., a computer memory, one or more floppy discs, compactdiscs, optical discs, magnetic tapes, flash memories, circuitconfigurations in Field Programmable Gate Arrays or other semiconductordevices, or other non-transitory medium or tangible computer storagemedium) encoded with one or more programs that, when executed on one ormore computers or other processors, perform methods that implement thevarious embodiments of the invention discussed above. The computerreadable medium or media can be transportable, such that the program orprograms stored thereon can be loaded onto one or more differentcomputers or other processors to implement various aspects of thepresent invention as discussed above.

The terms “program” or “software” are used herein in a generic sense torefer to any type of computer code or set of computer-executableinstructions that can be employed to program a computer or otherprocessor to implement various aspects of embodiments as discussedabove. Additionally, it should be appreciated that according to oneaspect, one or more computer programs that when executed perform methodsof the present invention need not reside on a single computer orprocessor, but may be distributed in a modular fashion amongst a numberof different computers or processors to implement various aspects of thepresent invention.

Computer-executable instructions may be in many forms, such as programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

Also, data structures may be stored in computer-readable media in anysuitable form. For simplicity of illustration, data structures may beshown to have fields that are related through location in the datastructure. Such relationships may likewise be achieved by assigningstorage for the fields with locations in a computer-readable medium thatconvey relationship between the fields. However, any suitable mechanismmay be used to establish a relationship between information in fields ofa data structure, including through the use of pointers, tags or othermechanisms that establish relationship between data elements.

Also, various inventive concepts may be embodied as one or more methods,of which an example has been provided. The acts performed as part of themethod may be ordered in any suitable way. Accordingly, embodiments maybe constructed in which acts are performed in an order different thanillustrated, which may include performing some acts simultaneously, eventhough shown as sequential acts in illustrative embodiments.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03.

What is claimed is:
 1. A locate receiver to detect a presence or anabsence of an underground facility, the locate receiver comprising: ahousing; an RF antenna for receiving a magnetic field and outputting anoutput signal; a processing circuit, for receiving the output signalfrom the RF antenna and determining a magnetic field strength of themagnetic field indicative of the presence or the absence of theunderground facility; at least one sensor, coupled to the housing, tooutput first geographic information indicative of at least onegeographic location of the locate receiver; a display device coupled tothe housing; at least one memory; and at least one processor, coupled tothe processing circuit, the at least one sensor, the display device, andthe at least one memory, the at least one processor configured to:display on the display device a digital image that is generated based onthe at least one geographic location of the locate receiver and based ondigital image data including at least one of facilities map data, surveymap data, land survey data, photographic image data, constructiondrawings, and engineering drawings; and overlay on the displayed digitalimage, based at least in part on the first geographic information outputby the at least one sensor, a plurality of electronic markingsindicating respective geographic locations of the locate receiver, anddetection of the presence or the absence of the underground facility atthe respective geographic locations of the locate receiver.
 2. Thelocate receiver of claim 1, wherein the locate receiver comprises atleast one actuation mechanism, and wherein the at least one processor isconfigured to generate at least one of the plurality of electronicmarkings in response to an actuation of the actuation mechanism.
 3. Thelocate receiver of claim 1, wherein at least one of the plurality ofelectronic markings is indicative of a detection of a facility line, andthe at least one processor is configured to generate the indication ofdetection of the facility line when the magnetic field strength exceedsa predefined threshold.
 4. The locate receiver of claim 1, wherein theprocessor is configured to obtain at least a portion of the digitalimage data from a remote device and store the at least the portion ofthe digital image data in the at least one memory.
 5. The locatereceiver of claim 4, wherein the at least the portion of the digitalimage data comprises the digital image.
 6. The locate receiver of claim5, wherein the at least one processor is configured to generate thedigital image based on the portion of the digital image data.
 7. Thelocate receiver of claim 1, wherein the digital image comprises a mapthat includes the at least one geographic location of the locatereceiver, and wherein the at least one processor is configured to causethe at least one geographic location of the locate receiver to beindicated on the digital image when displayed on the display device. 8.The locate receiver of claim 1, wherein: the digital image comprises afirst image layer; at least one of the plurality of electronic markingscomprises a second image layer; and the processor is configured to causeat least one of the first image layer and the second image layer to bedisplayed on the display device and cause at least one of the firstimage layer and the second image layer to not be displayed on thedisplay device.
 9. The locate receiver of claim 8, wherein the processoris configured to cause at least one of the first image layer and thesecond image layer to be displayed on the display device in response touser input, and to cause at least one of the first image layer and thesecond image layer to not be displayed on the display device in responseto user input.
 10. The locate receiver of claim 8, wherein the secondimage layer comprises at least two sub-layers, and wherein the processoris configured to cause at least one of the first sub-layer of the secondimage layer and the second sub-layer of the second image layer to bedisplayed on the display device or to cause at least one of the firstsub-layer of the at least two sub-layers and the second sub-layer of theat least two sub-layers to not be displayed on the display device. 11.The locate receiver of claim 10, wherein the first sub-layer of the atleast two sub-layers comprises an electronic marking corresponding to alocation at which an indication of detection of a facility line of afirst facility type was generated, and wherein the second sub-layer ofthe at least two sub-layers comprises an electronic markingcorresponding to a location at which an indication of detection of afacility line of a second facility type was generated.
 12. The locatereceiver of claim 10, wherein the first sub-layer of the second imagelayer is a timing sub-layer that includes an electronic representationof locates at which facility lines were detected during a defined timewindow.
 13. The locate receiver of claim 10, wherein the first sub-layerof the second image layer is a ticket sub-layer that includes displayedinformation relating to at least one aspect of a ticket for at least oneof the locate operation and a marking operation.
 14. The locate receiverof claim 13, wherein the at least one aspect of the ticket is at leastone of: a ticket number identifying the ticket; at least one partyidentifier representing a party requesting at least one of the locateoperation and the marking operation; at least one facility identifierrepresenting at least one of a type and number of one or more facilitiesto be at least one of detected and marked in at least one of the locateoperation and the marking operation; and at least one ground typeidentifier representing a ground type for at least one of a work siteand dig area at which at least one of the locate operation and themarking operation is performed; and the first sub-layer of the secondimage layer includes one or more of: a ticket number sub-layer; arequesting party sub-layer; a facility type sub-layer; and a ground typesub-layer.
 15. The locate receiver of claim 10, wherein the firstsub-layer of the second image layer is a service-related sub-layer thatincludes service-related information relating to at least one aspect ofat least one of the locate operation and a marking operation.
 16. Thelocate receiver of claim 15, wherein: the service-related informationincludes one or more of: at least one service provider identifierrepresenting a service provider overseeing performance of at least oneof the locate operation and the marking operation; at least onetechnician identifier representing a technician that performs at leastone of the locate operation and the marking operation; at least onedevice identifier representing at least one device used by thetechnician during at least one of the locate operation and the markingoperation; and at least one status identifier representing an operatingstatus of at least one aspect of the at least one device; and the firstsub-layer of the second image layer includes one or more of: a serviceprovider sub-layer; a technician sub-layer; a device sub-layer; and anoperating status sub-layer.
 17. The locate receiver of claim 10, whereinthe first sub-layer of the second image layer is a geographic sub-layercomprising an electronic representation of facility lines detected in aparticular geographic region.
 18. The locate receiver of claim 10,wherein the processor is configured to automatically select either thefirst sub-layer of the second image layer or the second sub-layer of thesecond image layer to be displayed on the display device.
 19. The locatereceiver of claim 10, wherein the processor is configured toautomatically select either the first sub-layer of the second imagelayer or the second sub-layer of the second image layer to be displayedon the display device based, at least in part, on a facility type that auser is attempting to detect using the locate receiver.
 20. The locatereceiver of claim 8, wherein the first image layer comprises at leasttwo sub-layers, wherein a first sub-layer of the first image layercomprises a first portion of the digital image, and wherein a secondsub-layer of the first image layer comprises a second portion of thedigital image, and wherein the processor is configured to cause thefirst sub-layer of at least one of the first image layer and the secondsub-layer of the first image layer to be displayed on the display deviceor to cause at least one of the first sub-layer of the first image layerand the second sub-layer of the first image layer to not be displayed onthe display device.
 21. The locate receiver of claim 20, wherein theprocessor is configured to cause at least one of the first sub-layer ofthe first image layer and the second sub-layer of the first image layerto be displayed on the display device in response to user input or isconfigured to cause at least one of the first sub-layer of the firstimage layer and the second sub-layer of the first image layer to not bedisplayed on the display device in response to user input.
 22. Thelocate receiver of claim 20, wherein the processor is configured toautomatically select either the first sub-layer of the first image layeror the second sub-layer of the first image layer to be displayed on thedisplay device.
 23. The locate receiver of claim 22, wherein theprocessor is configured to automatically select either the firstsub-layer of the first image layer or the second sub-layer of the firstimage layer to be displayed on the display device based, at least inpart, on a facility type that a user is attempting to detect using thelocate receiver.
 24. The locate receiver of claim 20, wherein the firstportion of the digital image is a portion of the digital image thatincludes images relating to landmarks.
 25. The locate receiver of claim20, wherein the first portion of the digital image is a portion of thedigital image that includes images relating to a type of landmark. 26.The locate receiver of claim 25, wherein the type of landmark is one of:telephone poles; fire hydrants; termination boxes; curbs; and manholecovers.
 27. The locate receiver of claim 20, wherein the first portionof the digital image is a portion of the digital image that includesimages relating to facility lines.
 28. The locate receiver of claim 20,wherein the first portion of the digital image is a portion of thedigital image that includes images relating to facility lines of aparticular facility type.
 29. The locate receiver of claim 20, whereinthe first portion of the digital image is a portion of the digital imagethat includes images relating to a dig area indicator indicative of ageographic area in which excavation is planned.
 30. The locate receiverof claim 20, wherein the first portion of the digital image is a portionof the digital image that includes images relating to facility linesowned by a particular entity.
 31. The locate receiver of claim 20,wherein the first portion of the digital image is a portion of thedigital image that includes images relating to facility lines in aparticular geographic region.
 32. The locate receiver of claim 20,wherein the first portion of the digital image is a portion of thedigital image that was originally generated during a particular timewindow.
 33. A method for displaying information on a locate receiverhaving a housing, an RF antenna for receiving a magnetic field andoutputting an output signal, a processing circuit, for receiving theoutput signal from the RF antenna and determining a magnetic fieldstrength of the magnetic field indicative of a presence or an absence ofan underground facility, at least one sensor coupled to the housing tooutput first geographic information indicative of a first geographiclocation of the locate receiver, a display device coupled to thehousing, at least one memory, and at least one processor,communicatively coupled to the processing circuit, the display device,the at least one sensor and the at least one memory, the methodcomprising: displaying on the display device a digital image that isgenerated based on the first geographic location of the locate receiverand based on digital image data including at least one of facilities mapdata, survey map data, land survey data, photographic image data,construction drawings, and engineering drawings; and overlaying on thedisplayed digital image, based at least in part on the first geographicinformation output by the at least one sensor, a plurality of electronicmarkings indicating respective geographic locations of the locatereceiver, and detection of the presence or the absence of theunderground facility at the respective geographic locations of thelocate receiver.
 34. The method of claim 33, wherein the locate receivercomprises at least one actuation mechanism, and wherein the methodfurther comprises: generating at least one of the plurality ofelectronic markings in response to an actuation of the actuationmechanism.
 35. The method of claim 33, wherein at least one of theplurality of electronic markings is indicative of a detection of afacility line, and the method further comprises: generating theindication of detection of the facility line when the magnetic fieldstrength exceeds a predefined threshold.
 36. The method of claim 33,further comprising: obtaining at least a portion of the digital imagedata from a remote device; and storing the at least the portion of thedigital image in the at least one memory.
 37. The method of claim 36,wherein the at least the portion of the digital image data comprises theat least one digital image.
 38. The method of claim 33, furthercomprising: generating the digital image based on the portion of thedigital image data.
 39. The method of claim 33, wherein the digitalimage comprises a map that includes the first geographic location of thelocate receiver, and wherein the method further comprises: causing thefirst geographic location of the locate receiver to be indicated on thedigital image when displayed on the display device.
 40. The method ofclaim 33, wherein the digital image comprises a first image layer,wherein at least one of the plurality of electronic markings comprises asecond image layer, and wherein the method further comprises: causing atleast one of the first image layer and the second image layer to bedisplayed on the display device and causing at least one of the firstimage layer and the second image layer to not be displayed on thedisplay device.
 41. The method of claim 33, wherein the act of causingat least one of the first image layer and the second image layer to bedisplayed on the display device and causing at least one of the firstimage layer and the second image layer to not be displayed on thedisplay device is performed in response to user input.
 42. The method ofclaim 40, wherein the second image layer comprises at least twosub-layers including a first sub-layer of the second image layer and asecond sub-layer of the second image layer, and wherein the methodfurther comprises: in response to user input, causing at least one ofthe first sub-layer of the at least two sub-layers and the secondsub-layer of the at least two sub-layers to be displayed on the displaydevice and, in response to user input, causing at least one of the firstsub-layer of the at least two sub-layers and the second sub-layer of theat least two sub-layers to not be displayed on the display device. 43.The method of claim 42, wherein the first sub-layer of the at least twosub-layers comprises an electronic marking corresponding to a locationat which an indication of detection of a facility line of a firstfacility type was generated, and wherein the second sub-layer of the atleast two sub-layers comprises an electronic marking corresponding to alocation at which an indication of detection of a facility line of asecond facility type was generated.
 44. The method of claim 40, whereinthe first sub-layer of the second image layer is a timing sub-layer thatincludes an electronic representation of locates at which facility lineswere detected during a defined time window.
 45. The method of claim 40,wherein the first sub-layer of the second image layer is a ticketsub-layer that includes displayed information relating to at least oneaspect of a ticket for at least one of the locate operation and amarking operation.
 46. The method of claim 45, wherein the at least oneaspect of the ticket is at least one of: a ticket number identifying theticket; at least one party identifier representing a party requesting atleast one of the locate operation and the marking operation; at leastone facility identifier representing at least one of a type and numberof one or more facilities to be detected or marked in at least one ofthe locate operation and the marking operation; and at least one groundtype identifier representing a ground type for at least one of a worksite and dig area at which at least one of the locate operation and themarking operation is performed; and the first sub-layer of the secondimage layer includes one or more of: a ticket number sub-layer; arequesting party sub-layer; a facility type sub-layer; and a ground typesub-layer.
 47. The method of claim 40, wherein the first sub-layer ofthe second image layer is a service-related sub-layer that includesservice-related information relating to at least one aspect of at leastone of the locate operation and a marking operation.
 48. The method ofclaim 47, wherein: the service-related information includes one or moreof: at least one service provider identifier representing a serviceprovider overseeing performance of at least one of the locate operationand the marking operation; at least one technician identifierrepresenting a technician that performs at least one of the locateoperation and the marking operation; at least one device identifierrepresenting at least one device used by the technician during at leastone of the locate operation and the marking operation; and at least onestatus identifier representing an operating status of at least oneaspect of the at least one device; and the first sub-layer of the secondimage layer includes one or more of: a service provider sub-layer; atechnician sub-layer; a device sub-layer; and an operating statussub-layer.
 49. The method of claim 40, wherein the first sub-layer ofthe second image layer is a geographic sub-layer comprising anelectronic representation of a location at which facility lines weredetected in a particular geographic region.
 50. The method of claim 40,further comprising: automatically selecting either the first sub-layerof the second image layer or the second sub-layer of the second imagelayer to be displayed on the display device.
 51. The method of claim 50,wherein either the first sub-layer of the second image layer or thesecond sub-layer of the second image layer is automatically selected tobe displayed on the display device based, at least in part, on a type offacility line that a user of the locate receiver is attempting to locateusing the locate receiver.
 52. The method of claim 40, wherein the firstimage layer comprises at least two sub-layers, wherein a first sub-layerof the first image layer comprises a first portion of the digital image,and wherein a second sub-layer of the first image layer comprises asecond portion of the digital image, and wherein the method furthercomprises: causing the first sub-layer of at least one of the firstimage layer and the second sub-layer of the first image layer to bedisplayed on the display device or causing the first sub-layer of atleast one of the first image layer and the second sub-layer of the firstimage layer to not be displayed on the display device.
 53. The method ofclaim 52, wherein causing at least one of the first sub-layer of thefirst image layer and the second sub-layer of the first image layer tobe displayed on the display device in response to user input or causingat least one of the first sub-layer of the first image layer and thesecond sub-layer of the first image layer to not be displayed on thedisplay device is performed in response to user input.
 54. The method ofclaim 52, further comprising: automatically selecting either the firstsub-layer of the first image layer or the second sub-layer of the firstimage layer to be displayed on the display device.
 55. The method claim54, wherein either the first sub-layer of the first image layer or thesecond sub-layer of the first image layer is automatically selected tobe displayed on the display device based, at least in part, on a type offacility line that a user of the locate receiver is attempting to locateusing the locate receiver.
 56. The method of claim 52, wherein the firstportion of the digital image is a portion of the digital image thatincludes images relating to landmarks.
 57. The method of claim 52,wherein the first portion of the digital image is a portion of thedigital image that includes images relating to a type of landmark. 58.The method of claim 57, wherein the type of landmark is one of:telephone poles; fire hydrants; termination boxes; curbs; and manholecovers.
 59. The method of claim 52, wherein the first portion of thedigital image is a portion of the digital image that includes imagesrelating to facility lines.
 60. The method of claim 52, wherein thefirst portion of the digital image is a portion of the digital imagethat includes images relating to facility lines of a particular facilitytype.
 61. The method of claim 52, wherein the first portion of thedigital image is a portion of the digital image that includes imagesrelating to a dig area indicator indicative of a geographic area inwhich excavation is planned.
 62. The method of claim 52, wherein thefirst portion of the digital image is a portion of the digital imagethat includes images relating to facility lines owned by a particularentity.
 63. The method of claim 52, wherein the first portion of thedigital image is a portion of the digital image that includes imagesrelating to facility lines in a particular geographic region.
 64. Themethod of claim 52, wherein the first portion of the digital image is aportion of the digital image that was originally generated during aparticular time window.
 65. At least one non-transitorycomputer-readable storage medium encoded with instructions that, whenexecuted on at least one processor in a locate receiver having ahousing, an RF antenna for receiving a magnetic field and outputting anoutput signal, a processing circuit, for receiving the output signalfrom the RF antenna and determining a magnetic field strength of themagnetic field indicative of a presence or an absence of an undergroundfacility, at least one sensor coupled to the housing to output firstgeographic information indicative of a first geographic location of thelocate receiver, a display device coupled to the housing, at least onememory, and at least one processor, communicatively coupled to theprocessing circuit, the display device, the at least one sensor and theat least one memory, causes the at least one processor to perform amethod comprising: displaying on the display device a digital image thatis generated based on the first geographic location of the locatereceiver and based on digital image data including at least one offacilities map data, survey map data, land survey data, photographicimage data, construction drawings, and engineering drawings; andoverlaying on the displayed digital image, based at least in part on thefirst geographic information output by the at least one sensor, aplurality of electronic markings indicating respective geographiclocations of the locate receiver, and detection of the presence or theabsence of the underground facility at the respective geographiclocations of the locate receiver.